Have you thought of going to a T-mobile store and purchasing a refurbish phone? I know Sprint does that for their Sprint customers. Perhaps the T-mobile store will help.
My sister just picked up the Shadow and now I want one it's pretty sweet it's between a smartphone and something like a sidekick and has some nice features like web access, email access(works with accts other than outlook ie. hotmail, gmail etc.), IMing, SD support so you can store music files as well as all of the normal phone stuff. If I didn't lose cell phones every other week I would buy this one right away. check it out at a tmobile store here's a review from cnet