As expected, music (dark blue) takes up more than a third of the space. The horizontal row of violet blocks is mostly Invader Zim episodes, and the vertical violet row under them is the three Reanimator movies, which I'd forgotten I had. I need to do something with those! Most of the other tan/orange blocks are other movies.
The big surprise for me is the huge green block (highlighted with a yellow boarder). That's Unreal Tournament 2004 vacuuming up 5.2 GB of my metal brain! I almost never play it on Gir, and I've got the install media, so I'll probably ditch it. The cluster of blue/grey blocks to the left of it are the various components of WoW. Roughly the same space, but that'll be staying. The orange cluster to the right of UT is TRON 2.0, which will also be staying, and the gazillion little yellow blocks to the right of that are my MAME ROMs. :-)
A nifty thing about Disk Inventory X is that it'll let you delete files right from the map. It also shows a tree view of the filesystem that jumps right to any point you click on in the diagram, and a bunch of other niftiness. If you've got a Mac that's running low on drive space, this is a pretty friggin' useful tool.
Okay, enough with the geeking out. Back to work with me.