I recently answered a question over at PhoneScoop.Com and I think it deserves its own post.

Did you know that you have the same 14 day remorse policy on upgrading your contract that you do when you activate new service? Well you do! All you need to do is call customer care and inform them you want to cancel the upgrade and have them back date your contract to reflect your remorse. Now if you got a phone with your upgrade they will want you to return it since you received a discount on your equipment.