Have old stuff you want to sell? Maybe some nice clothes you don't wear any more, an extra iPod, your old CD collections? People have been using listing services to do so for a long time. Craigslist provides local classifieds and forums for jobs, housing, for sale, personals, services as well as events, and is a leader in the field no doubt. The premier online auction site is eBay, offering antiques, collectibles and all sort of new items commanding the Lion's share of this marketplace.

However, with the increasing importance of Virtual Communities, where people interact and gather to share experiences and all sort of recommendations and tips with each other, the rules are changing. Now you can leverage the power of social networks such as MySpace and Facebook to promote goods amongst trusted friends of your virtual neighborhood.

Garage Sale is a new service available for Facebook members that allow them to post personal items for sale directly on their profile page and buy items from friends they know and trust - a great alternative to other online auction sites according to the developers. Once the sale is made, Garage Sale charges a 5% commission on the total sales price. No other setup or fees are required - if you don't sell, you aren't charged.

Mosoma is an auction platform for social networks. Members can now auction with the people they know best - each other. It also allows Facebook users to auction with the entire community, and is less expensive than eBay for items worth more than $10.

Some critics point to the fact that this new services lack access to the large pool of buyers eBay and Craigslist reach, because only their friends will see the listings, and sellers who are looking for a specific item are still likely to hop on over to these places and do a quick search. Nevertheless, there is an argument that a closed network is a better way to sell items because the people who view the listings know you and, presumably, trust you. eBay's feedback system provides information on the buyer and seller which helps them gets comfortable transacting. In the case of Garage Sale and Mosoma, user familiarity is the key.