Been there, done that, and the experience is awesome. I've waited in line for every iPhone and each and every time it was great. The boring wait part of it gets diluted and it almost becomes some type of party. Everyone there shares the enthusiasm for the iPhone so there is always something to talk about. It's just like a bunch of friends sitting around just hanging out. The time actually goes by really quick. I would highly recommend doing it at least once. And do it at an apple store if possible. But with that being said, get there early. I mean if it opens at 9am, get there at 5am at the VERY latest. If u want to get in and out, get there around 10-11 the night before and score a spot in the top 50.
And at an apple store I believe u have to be the account holder or they have to be with u. I am almost 100% sure of it. So make sure u call wherever u are going and tell them ur situation. That would be about the only thing that could totally ruin the experience of waiting in line. That and if the guy in front of u gets the last one.