I'm not from the US so i can't use Yahoo I have adsense on the site but i'm also thinking of using a banner along with adsense. Any ideas?
Figure out who uses your site. Is it a younger crowd and if so what do they like. Find some good affiliate programs like posters, t shirts and music and add banner or links to them.
The problem with proxies is you gotta remember these kids are at school. I don't know many kids who shop online at school (especially since most/all don't have credit cards, to boot.) Best to push crap like email/zip code submits. But there's other ways to monetize a proxy...