Where is my disk space? for Mac

From Landsbert:

Where is my Disk Space? was inspired by my brother whose hard disk was full up and he did not know where all the space had gone to. I had to trawl through all his folders finding out where all the space had gone. Using Sherlock found large files quite easily but was very slow. But it could not find folders that were using a lot of disk space, duplicate files, empty folder, or files which were part of a useless folder that could be trashed. Where is my disk space? analyses your hard disk and displays the results in size ordered windows so you can see where your disk space is being used up.