The FAQs and a number of old threads suggest that I can get use of the BB's full TCP/IP stack on T-Mobile with the APN setup in the BB's options. Unfortunately I don't seem to be able to get full TCP/IP functionality - Opera Mini doesn't work, SSH doesn't work, and IM+ falls back to HTTP mode.
I called T-Mobile tech support and bounced around between three call centers for 40 minutes before they finally hung up on me.
Anyone know what the proper settings are, or what the magic word to say to T-Mobile is to get this set up? I have the $19.99 Blackberry Unlimited plan.
Edit: the other BB data services work fine - built-in browser, IM, and email. Network status displays "EDGE" (all-caps).