If you use titanium backup, it has to have busybody to work properly. It will install a version if one isn't already installed. Other than that, there are a few other root apps that use busybox, I don't exactly have a list for you though, sorry.

 

I have to have a busybox installed--but that's mostly because I do a lot of adb shell work on my phone (i.e., navigating at the Linux command line level).

busybox is invaluable for that, IMO.

 

Other than the few apps that need it, I use it for fun.
I have cron running, I use it to reboot my phone on a schedule.
I use it to rename files or put ringtones and notifications in /system.
I use it to run sar just for fun.

 

Nope, you're good to go!

Its handy for certain manual things, but if you don't specifically have a need, then you shouldn't need to worry about it.

Cheers!

 

Vi is sort of nifty.

In a weird sort of way.