On XDA I’ve posted a little bit about busybox and what subprograms are inside. Here’s the link: http://forum.xda-developers.com/showthread.php?t=1509517
I’ve found busybox’s vi, find and grep most useful when I’m poking around in a terminal on my Motorola Atrix. I hope this helps someone, I believe busybox can be installed stand alone from the market, and is included in some other applications. Once you have busybox installed, sym linking it’s apps to the /system/bin (or something else on the path) makes Android a little bit more like linux.