Do I absolutely NEED a data plan just to use the new blackberry? I'm going to buy one off of ebay & just put my SIM card in it, but I can't do that unless I know for sure that it does not need a data plan just for running like a normal phone.

(P.s. don't say "just get a data plan" because I don't need it & I'm not giving at&t $30 a month for only a limited amount of data. A simple yes or no would be appreciated for this question.)