Windows/Mac/Linux (Adobe AIR): The marquee features added to social network aggregator TweetDeck are Google Buzz and Foursquare support, plus scheduled updates. What's actually useful, though, are the global filters that weed out oversharing, spam and other annoyances.
If you're a Buzz fan, or an active Foursquare user, you can now aggregate all your friends' social network check-ins into a single column, and automatically remove those same check-ins from Twitter and Facebook. You can also write tweets scheduled to go out later. Neat stuff, for the devoted followers.
What's really worth looking into, though, are the Global Filters, tucked into the settings. With them, you can screen and remove posts from any of the networks you're viewing through TweetDeck, whether based on people you don't want to see re-tweeted, key words you'd rather not get exposed to, or even particular sources, devices, or clients—though if you get that much noise through particular apps, maybe you're following the wrong people.
TweetDeck is a free download for Windows, Mac and Linux, and requires the Adobe AIR framework. By all means, tell us about the filters you'd like to apply to your web social life in the comments.
A Monster Update For Your Desktop [TweetDeck]