Reclaim Hard Disk Space From Dropbox Cache

I use Dropbox for most everything. It is keeping three home folders in sync.
Dropbox caches changed files on your hard drive. In the Finder click on the Go Menu and Choose > Go to Folder, and then enter ~/Dropbox/.dropbox.cache. If you have altered big files, then you can reclaim quite a bit of space. Likewise it is a easy way to go back and get a file that you want unchanged.