This little command is just the most basic proof of concept of a working live shell command. You can easily hack it up to run any random shell command you want. I'm planning of using something like this to implement a bunch of stuff soon.
TextMate Bookmarks, live updating. ZenTest autotest Mongrel server / Rails app log tail etc...
Feel free to suggest other interesting stuff.
 thomas Aylott — subtleGradient — CrazyEgg