The basic idea behind Yoink is similar to that of Freecycle: giving stuff away to people in your local area rather than just chucking it out. Yoink also maintains statistics on what you've given away, letting you see who the most generous people are in your area.
As well as the site, there's also an iPhone app for accessing Yoink. Yoink is a free service, requires signup. If you try giving something away on the site, tell us how it went in the comments.