Have you used Craigslist to buy stuff locally?
It feels very insecure and takes a long time to buy or sell. "Auction It" makes it easy to buy and sell stuff locally. Based on Ebay's philosophy, it allows users to list items as auctions with an end date or buy it now.
After someone purchases the item, the make immediate payment to "Auction It" where the money is held until the buyer receives the item. Seller and Buyer meet exchange item and they both mark purchase as OK.
Auction It takes a small commission and releases payment to the Seller.