Calling and texting are basic functions, for which you don't need a data plan. But pictures are data, so to mail pictures you need a data plan.
The alternative is to copy them to your PC (nice to have them there so you can make a backup and never lose them!) and e-mail them as an attachment. The e-mail on your PC includes a free data plan, so to say.
So I am with T-Mobile and I have passed my 2 year agreement with my razor. If I buy, say a blackberry or a tmobile G1 from a friend, will the phone still work with basic features such as calling, texting, and picture mailing?