Samsung and T-Mobile today launched the Samsung Blast (T729), a slider phone with a dual-tap QWERTY keypad similar to the SureType system on select BlackBerry handsets.  Blast also features an email client that supports GMail, Yahoo! mail, and user-definable POP/IMAP accounts out of the box. 

The handset also features MyFaves support, a 1.3 MP camera, a media player with Stereo Bluetooth support and MicroSD expansion, and quad-band GSM/EDGE connectivity.  Blast is available now from T-Mobile for $100 with a two-year service agreement.

Samsung's been pushing the envelope with US handsets over the past year or so, and the messaging-centric Blast reminds me somewhat of the Verizon-exclusive u740 dual-flip handset that came out earlier this year in that it's designed for text entry but not at all a smartphone.  Blast also fits in with T-Mobile's recent focus on messaging and personalization services like MyFaves, which appeal both to SMS-hungry teens and their value seeking parents. 

Look for a review of Blast on PhoneDog.com in the coming weeks.