The trendy HSDPA Clamshell device sony Ericsson TM506 is first ever 3G phone to be offered on T-Mobile's network. It is available now in T-Mobile outlets and online store on a two year contract costing $80 after $50 dollar rebate.

Here are the details:

Network: Triband GSM 850/1800/1900 MHz, Dual-Band UMTS 1700/2100 & 2100 MHz
Dimensions: 3.4 ounces weight, 3.7 x 1.9 x 0.69 inches size
Camera: 2.0 Megapixel Camera
Connectivity: GSM, GRPS, EDGE, UMTS, HSDPA, Bluetooth 2.0 A2DP
GPS: Built in aGPS, TeleNav® Navigator
Others: Music player, Media Center, IM (AOL, Yahoo, Windows Live, Google Talk), RSS Feeds, MyFaves-enabled, udio Postcard, Quicksend, Mobile Backup (T-Mobile Address Book)
Standby Time: Up to 250 hours GSM, up to 250 hours UMTS
Talk Time: Up to 9.5 hours GSM, up to 3.5 hours UMTS

Source: Mobile Crunch