Tesco, the largest supermarket chain in UK has begun buying second-hand games across the UK. For your games you'll be paid credit, which can be used to buy anything else in store: nappies, olives, cat food, drink, whatever. Adverts spotted by MCV tout a £19 trade-in price for Red Dead Redemption on Xbox 360. Mario Kart Wii fetches £19 and 2010 FIFA World Cup £12 on PS3. These games will be re-sold at applicable stores nationwide. Apparently around 60 Tesco outlets now accept pre-owned games. Every little helps.
http://www.eurogamer.net/articles/2010-08-20-tesco-buying-used-games-nationwide