I dunno. I know when you're out partying, things get expensive, and there's always hundreds of dollars flying in all directions between my freinds and I. I'm sure some of it has gone unaccounted for, and never repayed...But for the most part I think everyone is pretty good about making sure everything's on the level.
If a freind asked for $150, and I had it on me, I don't think I'd think twice about giving it (and I'm in Canada, where everyting costs twice as much to us as to you guys). I mean, I've spotted freinds at least as much just to keep them from going home from a night out, so why wouldn't I give it to them for an emergency? We all fuck up our little budgets sometimes, and it's nice to know that there are people you can count on to help you out if you fall short somewhere. Asking a freind, IMHO is far more respectable than calling home to your folks.