Volunteering at shows for tickets?

I have started considering this as a way to see shows I don't have cash for. Has anyone volunteered at festivals or shows? What are better positions to request?
I figure ticket tearing, parking directions, beer booths, children's art areas are possibilities. Waiting to hear back from a couple venues I have e-mailed.

 

parking is the most fun, even though i volunteered with many kids activities and enjoyed that, but it does cut into your festy time. you wont get ticket tearing or beer vendor unless you personally know the people running the event.
clean vibes is always a good way to go, because that is just 2 or 3 days of cleanup/groundscoring after the festival. parking imo is the best to get into, but usually run by an idependent non hippie company so its hard to worm your way in there. there are several groups that run the kid areas, but i am sure if you dont know the people, it might be hard to get in there. again kids tent is fun, but it car cut into your showtime. i always try to worm into parking volunteer (through the organizers) or cleanvibes. for cleanvibes you will most likely have to give them cash for your ticket before the show, and they pay you back after you pick up the cigarete butts for a day or two, then pay you cash if cleanup is longer.