Created by Mr. Paul Rawlings, the UK-based classified listing site Tweebay lets Twitterers to buy and sell their stuff on Twitter. Although it sounds quite familar to the popular online aution and shopping website - eBay, but it has no connection with neither Twitter nor eBay.
To use the service, you need not to provide your Twitter credentials and Tweebay only requires users to follow them on Twitter. You'll then receive a direct message to verify your account.
Buying and selling using this free service is simple. If you've an item to sell, you'd have to provide 240 characters to describe your item and a photo to accompany with it. Your listing will be up on Tweebay and to attract more buyers, you can automatically notify all your followers. To buy, you can confirm your bids via direct messages on Twitter.
Even though this is just a start-up that was launched a few days ago, it already has over 230 users trying out the service.