My students just introduced me to a fantastic tool for locating large files that may be hogging HD space. It’s called “Disk Inventory X” and can be downloaded for free from cnet. (It’s the green download bar on the left; don’t be fooled by the spam download bars)
Once you download it, run the .dmg file. You get a window where you can select the drive you want to inventory; choose your HD and select ‘open volume’.
A standard hierarchical view of your drive in the left pane shows you the total size of each folder or file. In the interface’s right pane is a colorful graphical representation of the types of files on your drive. Each file type is color-coded, so you can see how much space a particular type of file occupies. If you want to see all the tags and information associated with any file or folder, you need only click on it and a pop-up shows all the information the OS has on the item.
In my case, I saw a huge (35GB) folder that had a dozen videos in it, which was hiding in several layers of subfolders that I had imported when I moved from a PC to a Mac, and had transferred over through all of my computer replacements. I hadn’t seen or even thought of these videos for years, so it was easy to just delete them, and instantly I regained 35 GIGS of HD space.