Check out PartyPromoting.com - Learn how to Throw A Party and Get Paid!
Blog Summary:
Here I discuss one of many ways to throw a free party and still manage to monetize your door! Basically it involves using a cut line or VIP line to motivate people to get out of the long line that you hold on purpose 
Check out the video post here:
http://www.youtube.com/watch?v=0ILN3PA90is