well t-mobile does not let you send pics or any of that good stuff if you dont have a data plan. i dont have it on my phone so thats how i know, but if u do and its not working then something might be wrong with your phone or something.

 

For the sake of clarification, you don't need a data plan to send/receive MMS, just standard texting, for basic T-Mobile phones.

However for Android and Windows Mobile based PDAs, you can't activate them sans data plans anyway.