glyde
gazelle
BuyMyTronics.com
Amazon Trade-In
eBay Instant Sale
Swappa
NextWorth
Secure Trade-In
A Second Chance for Idle Electronics – NYTimes.com
Used smartphone market Swappa lets you safely buy an Android phone – Cell Phones & Mobile Device Technology News & Updates – Geek.com
Gadget Seller Beware: We Try Glyde Before iPad 3 Launch