With so many members on our board now, we've added the iTrader option to make it easier to see a member's past trading/buying history. Use this along with a user's eBay feedback (if their username is posted) to help determine if the transaction will be safe.
Each member's Feedback will be posted in their avatar and you can click on that link to see their detailed feedback.
Also, in the main navigation bar, I've added a link to "My iTrader" that will show your own feedback and rating.
Hope this helps and let me know if there is anything else I may have missed.