For example, suppose I wanted to see all the recent news-feed entries for mafia wars. Is there a way to filter your feed down to a specific application?
I can do this using the Facebook iPhone app client, but haven't figured out a way to do it in the browser interface to the site.
Best Answer
It does not seem to be possible. There is chatter in the Facebook Support Community but nothing to suggest that it is a feature right now.
There was a time where you could at least have priority of the filters by dragging but that seems to have been removed in the redesign.
For now until Facebook brings it back , you are going to be stuck with a add-on like Feed Filter or just stick those people you know use mafia wars into a Friend List .