So a few days ago I had my cellphone stolen. Now, I'm going to purchase a new one, and I've been looking at some on Ebay. These "unlocked" phones, do you just take them down to your service carrier and they set you up to your current network? Will I be able to keep my old phone number? Also, these sim cards that the phones have, if I buy one without it, will I be able to get one from my carrier? Basically I just want to buy a phone cheaper than it would be from the carrier and have them put all my old info back with that phone. Thanks guys