Once upon a time, one of the machines on our network was designated 'newpoot' and acted as the server because of the unimaginably huge 80Gb drive that it had. Over the years it has been patched and updated, and at some point set up to dual boot Ubuntu.
After looking at just how much space the windows partition was taking up on this machine when I have no need to actually ever use it, I bit the bullet and did a complete wipe and install of Ubuntu 10.10 from scratch. The whole process took just over half an hour, and once I'd put Dropbox and Firefox Sync on everything was back up and running smoothly.
As a result I now have over 60Gb of free space to play with that I didn't have before. Why didn't I do this before? The important documents are always backed up in Dropbox and everything else is backed up on the network storage drive, so a fresh install is nothing to worry about, and certainly much less stressful than the equivalent procedure in Windows.