Twitter overload? Don't despair. I introduced you to Tweet Deck recently as a way to help organize your flock into groups, but unfortunately, as an Adobe Air application, I've heard people say that it slows down their computers.
Alternatively, the download Nambu won't slow you down, but it will speed you through your Twitter friends' updates. Nambu is a free, native app (for OS X only), so it'll run quicker and smoother.
I also find it to be much easier to use and navigate, and the UI is classic Mac (look out for the Growl updates of your Twitter followers — something I love but something others may want to turn off!).