Here's the link to the referrals page over at DizPins, (which Pinpics is in conjunction with.)

All you have to do is add the email address of the person you'd like to check on and click submit. If they have been added to the get their trade comments history. VERY handy!

So please consider using this great resource if anyone decides to try online pintrading/selling/buying. It's best to be prepared and know a little about the practices of the person you are thinking about dealing with!