Godaddy Auction allow you to Sell or Buy Domains that are already registered.
Features
Buy Now - Want your domain name today? If a name you want displays Buy Now, just click the button and purchase it immediately.
Expired Domain Auctions - Place your bid on an expired domain name. If the auction ends and you're the highest bidder, the domain's yours.
Offer/Counteroffer - Make an offer on a domain and Go Daddy Auctions will instantly notify the seller, who then has the option of accepting or countering your bid.
7-Day Public Auction - Like a traditional online auction, sellers set a minimum starting bid price, and bidders place increasingly higher bids. When time runs out, if you have the highest bid, you win.
You need to pay $4.99/Year to join godaddy auctions while you can get a free 2 year accounts (with Domain Alert) by using the coupon code FREETDNAM
1. Go to Godaddy Autio - https://auctions.godaddy.com/
2. Click Join Now 
3. Select 2 Years from the drop down and click add to cart
4. Click No thanks on the next screen when it shows other products
5 Click "Enter Promo or Source Code"
6. Enter FREETDNAM and click apply
7. Proceed to check out (Total price will be 0)
8. Finish the steps, you may use your existing godaddy accounts also if you have any
[Via MegaLeecher]