Mashable has a list of 140+ Twitter applications! What's your favorite Twitter app and why do you use it?

We use twitterfox. It attaches to firefox and makes tweets pop-up in the lower right hand corner of your browser, so you can keep up without going back to twitter.com/home , and you can reply and tweet from the little box.

Wow! It's so amazing how Twitter has grown so much in recent months! Why is it so popular? It must scratch a serious itch. What itch does Twitter scratch?

And, 140 applications! We are firmly in the middle of Web 2.0 - perhaps Web 3.0 is when we start using hundreds of desktop applications that work in tandem with the internet to better gather, refine, and communicate information. It feels like a new age for the internet - something significant is happening. Do you feel it?

PS - Be sure & follow us if you aren't already - twitter.com/catalystatlanta