T-Mobile has formally announced its forthcoming myTouch 3G phone, the second mobile phone the carrier will offer based on the Google Android mobile operating system. The myTouch 3G will feature a 3.2-inch touchscreen display with a virtual keyboard for messaging, a 3.2 megapixel camera, access to all sorts of Google service (YouTube, Picassa, etc.) plus Android apps. And speaking of apps, T-Mobile is rolling in Sherpa, developed by Geodelic, that automatically customizes the phone based on user preferences and behaviors. As someone uses the myTouch 3G, Sherpa will pick up on their likes and dislikes, enabling it to prioritize things like search results and location-based information based on a user’s interests and behavior.

"T-Mobile myTouch 3G puts you first, so you can create a mobile experience that is truly your own," said T-Mobile’s chief marketing officer Denny Marie Post, in a statement. "There’s no cookie-cutter approach to myTouch. Inside and out, there are boundless possibilities for personalization so you can put your personal touch on the phone and make it uniquely yours."

The myTouch 3G is a rebranding of the HTC Magic; in addition to the 3.2-inch display and 3.2-megapixel camera, it features SD card expansion (it comes with a 4 GB card pre-installed), Wi-Fi and 3G mobile connectivity. The phone can top into Gmail, POP, IMAP, and Exchange mailboxes, handle IM with Google Talk, Yahoo Messenger, and Windows Live Messenger, and preview messages at a glance without quitting applications. The myTouch 3G is also lighter and features longer battery life than the T-Mobile G1, the operator’s existing Android-based handset.

The myTouch 3G will go on pre-sale July 8 for $199 with a two-year service agreement, with devices shipping in late July. The myTouch should be available at retail in early August.