AKA "Where did my space go?

This topic has been thoroughly covered in Finding biggest files, touched on somewhat in looking for a simple solution, and has probably been covered in many other nodes that I didn't have time to look up. Still, when I was cleaning up my hard drive and thought of this the other day, I thought it was pretty clever.

What does it do? It filters the output of du (disk usage), letting you set the size of files/directories you want to see. (E.g., suppose you want to see which files/directories use more than 1000 blocks, or you want to know which are between 900-1000 blocks, etc.)