My mom got the iphone 4 and gave me her 3gs. It's a great phone, but I'm having trouble because some of the apps that I want will not run unless I have it updated to the most recent os before 4.0. Is there a way to do this? I think it's on 3.1 right now and needs to be on like... 3.1.2 or something. Anyone know a way to do this?