I literally just went and bought a Sony-Ericsson TM506 today. It's the only 3G tmobile phone that supports both HSDPA(Faster than UTMS) and DUN tethering. I'm in the NE side of San Antonio, so T-Mo's 3g has been out here for a while.

After about three hours of messing with settings, I've finally gotten it to work.

T-Mo EDGE speeds: 26kbps download
T-Mo 3G speeds: 755kbps download

I don't know if the BT connection is the bottleneck here, but i can play youtube videos and stream vagalume now, whereas on EDGE it was basically a waste.

Also, first post!

-Mifty