The T-Mobile G1 is the first cell phone to come to market with the Android operating system created by Google. Android is an open-source platform that caused a lot of buzz in the industry and brings new competition to established platforms like Windows Mobile, Symbian, Palm OS, and possibly even the iPhone OS. The T-Mobile G1 gave us the first possible opportunity to see how the Android OS performs and comes on hardware manufactured by HTC. It's offered by T-Mobile at $179 with a 2-year contract.

The T-Mobile G1 is a fairly substantial device with a large touchscreen and a full QWERTY keyboard that slides out from underneath. The touchscreen can be used in portrait mode, but any text entry must be done with the QWERTY keyboard, which automatically switches the screen to landscope mode when exposed. The only on-screen entry that can be done is dialing a phone number - the G1 has a good on-screen keypad that is quick and responsive. All in all, it can get a bit tedious to use the G1 if you don't always need the keyboard and must frequently open and close it when you need to enter text periodically, though the interface is pretty responsive for all activities.

The G1 can sync with your PIM data, but out of the box it's only capable of doing this with the data in your online Google accounts. If you use a common desktop application on your computer, you have no way to sync this data directly to the G1. The G1 is a good choice if you already use the Google online applications to manage your personal information, or if you're okay switching to them specifically for use with the G1 or finding some other way to keep your desktop in the syncing loop as well. Other than this syncing issue, the G1's contacts application offers good flexibility to record a lot of information about your contacts, though its calendar doesn't offer the level of detail and information the typical business user would need. The G1 does not come with a Notes or Tasks application out of the box.

The G1 has 2 separate email applications - one for your Gmail account and another for all other email accounts, up to 5, that you set up on the device. Each app offers slightly different levels of functionality, but they work well and are fairly intuitive to navigate.  The G1 also has good instant messaging capability, though each message sent and received will be charged as a text message, except when you're using your Google Talk account.

The G1's music application is capable but it's here that we see some UI inconsistencies with contextual menus to create playlists and other actions. Regardless of this, playlists can be created and edited directly on the G1 and songs can be selected as ringtones right from this application, though you can't control which portion of the song is used. The G1 also includes an app to directly shop from the Amazon MP3 store and download music right to your phone, though downloading purchased music can only be done when connected to a Wi-Fi network. The G1 does not have a video player application out of the box, so you'll have to find a 3rd-party application to watch videos on it.

The G1 is a quad-band GSM device, offering the best level of network compatibility for international travelers. It also has Wi-Fi, Bluetooth, and GPS. Bluetooth is a little limited, with only 2 profiles for headset and handsfree device use.

Performance (read the full lab performance results at wirelessinfo.com)

The G1 sent and received audio quality is good, with only minor issues. Its side tone is a bit high, however - side tone is the amount of your own voice piped back to you to help you judge how loudly you're speaking, and side tone that's too high will make you think you're speaking too loudly even when you're not and cause you to adjust accordingly.

The G1 has a 3.2-megapixel camera with an auto-focus lens that performed worse than expected, with lower scores in resolution, color, and noise than comparable phones with the same or even lower-megapixel sensors. Taking pictures is easy with a dedicated camera shutter button on the left side and a straightforward camera interface. The G1 cannot capture video out of the box.

In terms of battery life, the G1 performed better than the claimed talk time battery life by almost a half an hour, lasting for  5 hours and 27 minutes.  This isn't bad for a 3G phone that uses a power-hungry cellular radio on a power-intensive network standard and is on par with comparable devices. Music playback and web browsing battery life are decent as well at 7 hours and 23 minutes and 5 hours and 10 minutes respectively.

Comparisons (read more in-depth comparisons at wirelessinfo.com)

The T-Mobile G1 is an iPhone competitor in the eyes of many, though it doesn't quite stack up with far less internal storage, a less-intuitive interface, and fewer multimedia capabilities. Looking at other smartphones like the HTC Touch Diamond and the Nokia E71, the G1 is far less able to satisfy business users without desktop PIM syncing, Exchange server syncing capability, and the level of extensibility both devices have with their well-established operating systems. Considering another T-Mobile offering, the Sidekick LX, the G1 is a viable alternative that offers more flexibility with its growing library of 3rd-party applications and a touchscreen in addition to its full keyboard.

The G1 is a solid device for the debut of a new operating system, but lacks the polish and extensibility of other devices with more established platforms, even including the iPhone 3G. Hardware-wise, the G1 is not sexy or sleek but it offers a full QWERTY keyboard for those who prefer this instead of using a virtual on-screen keyboard that provides no tactile feedback. Time will tell how well Android matures and how much its 3rd-party application offerings will grow, making it a good buy if you're patient or you want to check out the new kid on the block.

For a more in-depth review, visit the T-Mobile G1 Review at our partner WirelessInfo.com.