Peep the scenario: You’re stuck with a Samsung Galaxy S III or last year’s MacBook Air and looking to stay relevant with the times by copping the latest models heading into Q3 2013. Problem is the cash flow is looking thirstier than Wesley Snipes’ bank account and the only true collateral at your disposal is a collection of outdated gizmos. If this sounds all too familiar, then it's time to take that next step—selling your old gadgets online. The Internet plays host to a variety of different re-commerce domains, which allows users to push their unwanted electronics for sale, or in most cases, buy back and compensate them via cash (or credit) for such devices. Hey, it beats Craigslist. So start saving up for the iPhone 5S now by becoming familiar with The Best Internet Sites to Sell Old Gadgets.