Bonnie - I admit I hide pretty much all games from my feeds because otherwise when I went on facebook all I would see is my game-playing friends playing their games
Just put your mouse to the right of any post like that, and a hide option will appear.
It's interesting, on Facebook I would rather not friend someone who I didn't intend on following. But on Twitter, back in the early days I followed everyone who followed me - and ended up with some who were more spammy then I would like. Since I use TweetDeck to do my Twittering, I just dropped them off my list of viewable posts rather than un-following them.
I imagine if I was still using Twitter on a system where the main stream was filled with every single post, that I would have to start un-following people at this point to keep it manageable.