Disk Cartography is a disk usage analyzing utility that might prove to be of good use if you're dealing with low disk space. This program helps you immediately identify the large files and folders that take a large chunk of disk space and provides you with a simple way to remove them from your Mac.
Beside analyzing local drives, this program is also capable of scanning the contents of individual directories from your Mac, USB sticks, memory cards, etc. The scanning process takes a small amount of time, even when analyzing large-sized drives or folders. Once the scan is complete, the application gives you access a tree-view representation of the analyzed folders, indicating the largest files and directories with a red line (the red line is displayed on the right side of the screen, next to the file or folder in question).
This utility is more than just a disk usage analyzing tool. It's also capable of batch removing the found files without leaving any traces behind.
Another great aspect about this program is the fact that it can find and display the hidden files from your Mac. It also keeps a log with all of the completed scans and data removals.
To summarize, I can't find a single bad thing to say about Disk Cartography. It does exactly what's being said on its homepage. Plus, you don't have to pay a buck to use it on your Mac.