Question about AT&T Wireless.

Hey there, i was just curious about a certain phone plan. i currently use alltel wireless and have a prepaid phone. i love the coverage, get great signal, but i want a smart phone. and on alltel's network you HAVE to have a "Smart plan" when i add up the plan plus unlimited messaging, it comes to about 100 a month with tax and everything, for just me.. im not really wanting to pay that much. with AT&T you dont have to have a smart plan to have a pda or smartphone. so we're lookin more around $59. plus tax. anyway.. when you sign a two year contract (i'm a 20 year old male) do they require a deposit? alltel wanted 300 from me.. ON TOP of the plan charge plus phone price. it was like 550 for everything. will at&t charge me hundreds for a deposit?