That's a good idea. You can do that on the auction site. If you are interested in a auction and want to see what others are saying about the sell or one of the bidders.
Click on that auction your interested in, then click on the seller and or bidders name. There you can read what others have said or leave comments of your own regarding your experiences with that bidder or seller. I encourage everyone to do that!
I will come up with some tips and post them. Also I will add a forum for extra comments and wanted items.