Free stuff is the best, but what if you really really wanted that box of barbed wire and lollipops being given away on Craigslist, but some other dude snatched it first, and he didn't even want the barbed wire?!? Letting you score stuff people're ditching by proving how much you want it, Listia.
Built by Silicon Valley vets and designed to function like eBay for all things gratis, Listia lets users place stuff they want to unload into online auctions that utilize a proxy bidding system that accepts credits earned (for free) on the site, meaning the highest bidder takes home the sack of malnourished Tamagotchis, not just the one who saw it first. To get in on the action, take the 100 credits they give you for signing up, browse items by location or category (DVDs & Movies, Sporting Goods, Cell Phones, etc) and start bidding; auctions last 7 days, and if you win, your bid credits transfer immediately to the account of the user who listed it, so there's no delay before he can shower himself in his no-money. Listia recommends searching for stuff in your area to eliminate shipping costs on either end, and also dishes out credits to users for things like referring a friend and listing items yourself, although they sell extras for 10 for a buck; right now, active high bids include 500 for a used BlackBerry Pearl, 50 for a used copy of Madden '08 for PS3, and only 6 for the book Eat Pray Love -- and here you've just been settling for eat.
As an added incentive to earn more credits, Listia sponsors ongoing "Rewards Auctions" for legitimately great new items, like flatscreen TVs, HD camcorders, etc, which rack up hefty bids you can't top unless you're swimming in credits -- potentially leaving you to do your swimming in a slightly used kiddie pool, if that dude who wants the kid who comes with it doesn't get there first.