I use Twhirl. It does exactly what you are looking for.
Source(s):
http://www.twhirl.org/

Permalink | Report

I use Twhirl, it sits nicely in the corner and streams what people are saying, here is how it looks...

http://www.flickr.com/photos/33749589@N07/3178141268/
Source(s):
http://www.mahalo.com/Twhirl

Permalink | Report

I'm partial to Spaz. It's an AIR app, like Twhirl http://funkatron.com/spaz You can see your stream, do replies, and when it's minimized, you get a nice, compact fade-in with the update.
Permalink | Report

I like Twirl!
http://twirl.org
Source(s):
http://twirl.org

Permalink | Report

tweetdeck is best if you follow a lot of people or want to do live searches
it's an air app like twhirl and thus runs on linux, mac and windows

http://www.tweetdeck.com/

twirl is best if you want to use friendfeed, seesmic and/or laconica as well as twitter
Permalink | Report

bDule ( http://www.bdule.com ). Best client ive seen so far. Built on C# WPF goodness.
Permalink | Report