Iphone help!!!!!

I recently purchased an iphone 3g black. If i buy a at&t prepaid 3g sim will i be able to use prepaid at&t cards on it.

 

Yes, that should work however i would check out the link below for a little more information about it.

Code:

http://forum.ecoustics.com/bbs/messages/34579/371340.html

 

thx alot 1227

 

so once i buy the 3g prepaid sim card (the one i bouhgt online did not come with a sim card) will it give me a new phone number? also do i need to jail break it?