I sell my stuff on the Overclock.net marketplace. You need 35 reputation points to create a thread in the market but anyone can respond. It's a lot safer than Ebay, and much faster and less annoying than dealing with flaky craigslisters. The 35 rep is difficult to get, but can be done in a month or less if you work hard at helping people. I did it in about a month.
You can also sell stuff here or at other tech forums like techpowerup.com and the rules are less stringent but more likely to be abused.