Is there a program that can tell me what the biggest files on my computer are?

I have an old computer with a very small HDD (80GB) and it's totally full. I've moved most of my personal files to an external, but I still need to clean up the drive. CCleaner can free up a few MB, but I'm really want to know which files and folders are taking up the most space, and it takes a long time to href='http://tennalapplt2.vilablog.com/2011/02/21/shouldt-the-republcan-base-be-a-bit-smart/'>right-click each folder to get a space usage summary. Is there a program that can scan your computer for large files and folders to help you clean up? It would be nice if it could make like pie charts of which programs are using how much space, or which filetypes are taking up what percentage of your HDD so I can get a feel for my HDD usage. Thanks for any help!