For months the two companies have competed in the mobile-phone market thanks to Google’s Android operating system, and that competition is fiercer now that Google has stamped its logo on the back of the Nexus One (designed by Google and manufactured by HTC). Despite some differences, the new Google smartphone looks a lot like an iPhone.

There’s competition on other fronts as well, including the operating system business.

In its initial blog post in July, Google positioned Chrome OS as “an open source, lightweight operating system that will initially be targeted at netbooks.” That alone could harm Apple if Chrome-powered netbooks take sales away from Mac laptops. But now there’s talk about both Chrome and Android being used on tablet devices that could compete with Apple’s just announced iPad.

Concept of what a Google tablet might look like (source: Google)

There have been no product announcements, but Google’s Chrome Web site is displaying “visual explorations of how a Chrome OS tablet UI (user interface) might look in hardware.” The illustrations provide only a vague idea of what such a tablet might be like, but their very existence indicates that Google may be eyeing the market that Apple hopes to bust open.

Just in case one tablet operating system isn’t enough of a threat to Apple, Google is potentially going after the iPad with two operating systems at once. Android, in addition to Chrome, could also be used to create a potential iPad killer.

At last month’s Consumer Electronics Show, MSI displayed a 10-inch tablet running Google’s Android operating system.

It’s important to emphasize that neither the Google concept drawings nor the MSI prototype represents a real product. But what they do represent is the possibility, and perhaps the intention, of Google to quickly enter the tablet marketplace.

To be sure, there are important differences between Apple and Google. Apple is more focused and disciplined — it works long and hard on a very small number of products and keeps quiet about them until they’re almost ready for prime time. Then, with great fanfare, Steve Jobs announces them to the world and puts them on sale shortly thereafter.

Google throws lots of things against the wall to see what sticks. The company’s experimental culture is so strong that employees are allowed to devote 20 percent of their time to any project that strikes their fancy, some of which actually see the light of day as products or services.

Apple’s formula — at least with the iPhone — worked like a charm. The hype was followed by a product that delighted most early reviewers and customers. And although I questioned in last week’s column whether the iPad can live up to its hype, I acknowledge that it is an innovative product that might do well when it hits the market.

Google’s approach is usually to pre-announce months in advance and rely on partners like HTC (and now Motorola) to build devices around its open source software. Unlike the first iPhone, the initial Android phone — the HTC G1 — got tepid reviews. But with the release of the Motorola Droid and Google’s Nexus One, Android is starting to win fans and respect.

Google’s initial foray into the browser market was also a bit disappointing but that, too, is starting to change. When the Chrome browser came out, it was a bit faster than market leaders Internet Explorer and Firefox but not nearly as versatile because it lacked support for extensions that allow third parties to add functionality. However, Google recently released a beta version of Chrome that fixes that problem.

Last month Chrome overtook Apple’s Safari as the third-place browser behind Internet Explorer and Firefox, according to Net Applications. As more extensions become available and more people download the newer version, I’m confident its market share will continue to grow.

The biggest difference between Apple and Google has to do with control. Apps for both the iPhone and iPad will be distributed through Apple and be vetted and approved by Apple before being made available to users. Google has a more open approach, allowing anyone to create an app for their phone or their computer operating system.

The democrat (small d) in me sides with Google. But the part of me that’s concerned about safety and security understands the advantages of having a company like Apple examine the applications for its devices.

Mostly I’m just glad to see these two talented and resourceful companies compete with each other and, of course, Microsoft, which was once thought to be a monopoly but is now struggling to compete with both Google and Apple.

This post is adapted from a column by Larry Magid that appeared in the San Jose Mercury News

The phone, which is manufactured by Taiwan-based HTC Corporation, will be available from T-Mobile starting Oct. 22 for $179, with a two year contract.

Like the Apple iPhone, it features a touch screen (3.2 inch) to easily launch applications but there are also five dedicated buttons, including very handy menu and home buttons, plus a trackball.

If you want to make a phone call while holding it in portrait mode you can bring up an onscreen dial-pad, but if you want to enter text – perhaps to respond to an email or access a web page, you have to turn the phone on its side and slide out the physical QWERTY keyboard.

I like having a physical keyboard – the lack of one is my major complaint about the iPhone. The keyboard is okay, but I prefer the extra travel you get when pressing keys on the Blackberry Curve. Without a backlight, the G1 keys are hard to see in the dark.

When you slide out the keyboard, the phone goes from portrait to landscape mode but it doesn’t do that just by moving the phone.

I’m surprised and disappointed that it doesn’t give you the option of also bringing up an onscreen keyboard for typing text. Seems to me they could have offered that along with the physical keyboard but perhaps that will be corrected with a software update or a third party application.

And therein lies the real promise behind this phone. Like the iPhone, there is an icon on the main screen that brings you to an application store (it’s called the “Market”) where you can download applications provided by independent developers.

So far there are only about 40 such applications, compared to thousands for the iPhone, but if Google is successful in evangelizing Android, it’s safe to assume that a lot more applications will be forthcoming.

Unlike Apple, Google and the cell phone carriers have said that they will permit virtually any application – even if it competes with the economic interest of those companies. For example, there is already an application called iSkoop that lets you make free or inexpensive international and domestic calls using Skype. Warning to merchants – my favorite application lets you use the phone’s camera to “scan” a product’s bar code to look up reviews and comparative prices.

The G1 comes with only one gigabyte of memory compared to eight gigabytes for the $199 iPhone or 16 GB for Apple’s $299 version. However, the G1′s memory is on a removable microSD card, making it very easy and reasonably affordable to expand the memory up to 8 gigabytes now and, probably, 16 or more in the future. An 8 GB card can be purchased for about $25.

As you might expect, the G1 comes with a dedicated Gmail and Google calendar application where your mail and calendar are always in synch with Google’s web-based applications. This can be extremely convenient if you regularly use Gmail and Google calendar on your PC or Mac, but possibly a deal-breaker if you’re not a Gmail or Google Calendar user.

There is another email application that works with other POP3 and IMAP email accounts but, so far, not Microsoft Exchange mail which is used by many companies.

Unlike every other smart phone I’ve used, the G1 doesn’t come with software to synchronize your calendar or address book with a PC or Mac, which could be a big problem for many people but not for those who already use Gmail or Google Calendar. Microsoft Outlook users can get their data into the G1 by first using free PC software to synch with Google’s web applications.

The phone does come with a USB cable to transfer music or photos between the phone and a PC or Mac. Unlike Apple products, it uses the same standard Mini-USB connector as the Blackberry and many digital cameras. You can also charge the device from a computer’s USB port.

The interface is pretty intuitive. You get a relatively sparse home screen but you can reveal all of the applications by tapping or dragging a tab on the screen. There are actually three main screens that you move between by flicking in an iPhone like gesture. You can bring up a menu to add any application or icon to any screen by holding down your finger for a few seconds. It’s not intuitive but it’s easy to use once you figure it out. Like the BlackBerry, but unlike the iPhone, you can make a call by just typing the person’s name from the home screen.

The G1 has the second best web browser I’ve seen on a phone – almost as good as the iPhone’s. The G1′s browser does let you use your finger to move about the screen and you can zoom in or out by taping on a plus or minus icon. That’s not bad, but not as good as using two fingers to pinch and zoom or contract an image on the iPhone. When you’re in the browser you can press the menu to bring up screens to enter a URL, search, set a bookmark or switch to a new browser window. This is a pretty versatile browser for a hand held device.

There is also an Instant Message program that supports AIM, Google Talk, Windows Live Messenger and Yahoo Messenger.

The phone does have GPS and Google Maps. You don’t get turn-by-turn directions but I was able to easily use the map application to help me find an address on a recent car trip. You can view the map from street or satellite view.

The G1 does have a music player and it comes with a stereo headset that connects to the USB port. Unlike the iPhone and the consumer oriented BlackBerries, there isn’t a standard audio jack. I think that’s a real shame especially for people who like to use higher-end headphones, plug music players into a car stereo or, like me, tend to lose headsets.

I’m told that an optional adapter is available but that’s one more thing to buy and possibly lose. Although it supports Bluetooth headsets for talking on the phone, it doesn’t support stereo Bluetooth music headphones.

In addition to transferring music from a computer, you can purchase songs via the Amazon MP3 store. The songs are unencrypted and you can copy them from the G1 to a PC or Mac by connecting the two devices with a USB cable and dragging the file as if between disk drives. There is no synch program like iTunes.

If you’re a YouTube fan, you have plenty to watch but that’s it when it comes to video. That’s a glaring omission which, I hope, will be remedied by third party developers.

The G1 phone works on T-Mobile’s high-speed G3 network as well as its slower Edge network. I found G3 coverage in most, but not all, parts of the San Francisco and Los Angeles areas where I tested the phone and I was pleased to be able to get coverage, albeit a bit slower, at several car stops between the two cities on U.S. 101 and Interstate 5.

Depending on use, the battery typically gave me between about 3 and 4.5 hours of use but, unlike the iPhone, the battery is removable so heavy users can bring along a spare.

T-Mobile’s $25 data plan includes unlimited email, web access, 400 text messages and Google Talk access. For $10 more you get unlimited text messages and instant messages. Both plans give you access to T-Mobile WiFi hotspots. You’re also required to have voice plan starting at $30 a month.

Bottom line: The G1 is an excellent phone but lacks a bit of the fit and finish of the iPhone. It’s easy to use but not as intuitive as the iPhone. I like it a lot better than any Windows Mobile phone and – for consumers – it competes well against the BlackBerry but doesn’t bury it. It’s definitely not ready for corporate use.

Of course, this is only the first of the Android phones. Google’s Open Handset Alliance includes many carriers, including Sprint and cell phone makers LG, Samsung and Motorola. Over time we’ll see a lot of choices including phones with different form factors than the G1 as well as new applications.

Still, if you want to be among the first to play with Google’s entry into the phone application market, the G1 will serve you well.