Do you have an old cell phone, MP3 player or PDA device just sitting around? Most of us do, and Second Rotation aims to help us get rid of them and make some money doing it. Second Rotation buys back old consumer electronics and sells them on eBay for you. All you have to do is use estimate the value of your product (using their step-by-step guide), ship it (they will even pick it up at your house), and wait for your check (after they've checked out your gadget that it). In order to do this, Second Rotation is mashing up data from eBay to check current prices. It makes money by buying your goods a bit cheaper than what it thinks it can sell them for on eBay. Second Rotation lists about 2,500 items and intends to expand to about 5,000 items in the coming months. The categories are cell phones, digital cameras, digital music players, camcorders and GPS devices.