I currently have about 12 tabs open on my browser. Only 6 of them show; the others are buried in a list. One of my teachers at work always has about 26 tabs open in his browser. It is very unwieldy and hard to keep track of all the different tabs. I'm always inadvertantly closing something I actually need.
It's still in Beta, but Firefox is working on a solution to all of this, and it looks sweet. Here's the video.
An Introduction to Firefox's Tab Candy from Aza Raskin on Vimeo.