Ok, I think I know how to get the iPhone working on Net 10 prepaid service. Net 10's service and sim cards are weird. You can't just jailbreak an iPhone then put the Net 10 Sim Card in it (because Net 10's Sim Cards only work for the phone they're programed for), first you have to call up net 10, tell them whats up, u know give them info from your Sim and iphone, then they send you a new Sim Card with the info on it (for free if i might add), and then (if I'm correct) you can put the Sim card in the iPhone and voila! Good Luck!
Incase you're wondering how i put this all together I did call up Net 10 and they were very helpful with guiding me through it. The whole process involved using the serial number on the back of your iPhone, and their Sim Cards. The only reason I didn't follow through is because I was impatient and went with AT&T prepaid, which has been working good for me so far.