Sell pieces of pie for eating as well as throwing. Contact a local store and do holiday wrapping. Charge by size of box you are wrapping. If you do it for a couple of weeks daily before the holidays you can raise some major dollars. Find people who will volunteer to kiss a pig if they receive the most votes.
People vote with money for the person they want to kiss a pig.
All of these are great ideas to get you started. Not everything will work for every youth group, but hopefully these ideas can get you started.