How do I filter my facebook friends by the games they play?

[CNN]

I need to restrict the friends that see my game posts so I want to create lists according to the games that my friends play and use those lists to restrict the game posts.
The problem I'm having is that I don't know which of my friends play which games. So creating a list is difficult. Doesn't facebook have a filter to show which friends play certain games?

[Mark]

from your home page, left hand side create a group.

Add all your gaming friends to this new group, then when you post on your wall you can decide if to all your friends or not.

I don't know is this will work with games that automatically post though like Farmville etc.