Can i buy a smart phone at full retail with no 2yr contract and not get a data plan?

is it true if you do get a 2 year contract or rebate you have to get the data plan,but what if i buy the phone at full retail from the store will i need a data plan,i herd u dont if u pay the full retail,i had a palm centro since 08 but broke the screen and need a new phone maybe the htc fuze.