As a current iPhone 3G user, I'm switching to Sprint and getting a Pre on Saturday. I have limited credit history, however, so I called Sprint to request a credit check. They were more than happy to do so. It seems that I had actually added a fraud alert to my credit file and so Sprint could not give me any info over the phone, so I'll have to go to a Sprint store with two forms of ID. I'm just posting to let others know you can get your credit checked before you stand in line at the store.

FYI, Sprint soft-pulled (does not affect your credit score, unlike a HARD pull) my Equifax report. I assume that when you actually sign up for service, they'll perform a hard pull which will affect your score.