If you’re like me—and you’d best hope you’re not—you leave tabs open a lot. Lots of tabs. Lots . “Angels dancing on the head of a pin” amounts of tabs. It’s annoying: for one thing, it can bog down the computer, but for another, it becomes hard to tell which are the tabs you really don’t need any more.
Aging Tabs extension for Firefox, which cleverly fades your tabs based on how long you’ve had them open. Tabs can be aged whenever you switch tabs, change a URL, or a certain number of seconds elapse, and you can choose how much older they get on each increment.
Very handy for making you at least go through your older tabs and cull them, if nothing else. Now, if only there was a similar solution for Safari.