eBay
Buy or sell a wide variety of items online.

eBid
Buy or sell a wide variety of items.

Heritage Auction
Buy or sell collectables. You may also use this site to determine their value.

ShopGoodWill.com
Sponsored by GoodWill industries this site provides the convenience of an auction while helping the charity.

Waddingtons Auction House
Located in Canada this site allows you to browse for auctions in which you may be interested.