At eBay, list your qualifying Apple, Samsung, HTC, BlackBerry, or LG Smartphone via a 5-, 7-, or 10-day auction-style format (or auction plus Buy It Now), and if it doesn't sell, you'll receive a $100 eBay coupon for free as part of its Flip Your Phone For The Win Event. (Subject to certain conditions.) A list of all eligible phones as well as terms & conditions are available here. Deal ends October 14.