Earlier this week in the MacNN forums, Forum Regular PeterParker started a thread proudly announcing the purchase of their new (used) iMac from eBay, and they are wondering if there is a way to find out if it is in tip top shape, or if there are hidden problems waiting to erupt. Forum members discuss why and how to use Screen Sharing in this thread started by Junior Member Harvey earlier this week after an inquiry was made about this built-in feature.