For any Red Sox fans like me who are into Schadenfreude, the NYYFans forum can be pretty damn entertaining when things are going sour in Yankeeland.
Yesterday on their thread about the trade deadline, a guy kept posting pictures of Cashman in a sleeping bag (the homeless thing he does every year).
It allows for comparisons between all players, but you have to allow for differences in volume, for example, you can't compare a pitcher with 50 innings to a pitcher with 5 innings, apples-to-apples.