Accourding to your mount info, your /home directory is part of root..
anything in home you can get rid of ? old out of date downloads, old .iso files from your last upgrade, pacckage cache files from your distro updates, etc ?
You didn't mention what distro you have, and it's not listed in your profile, so it's hard to point you to these items.. if you are running a Debian based distro (Debian, Ubuntu, Simply Mepis, etc.. ) you can do an apt-get clean && apt-get autoclean to clear out the package cache of files the system downloaded during the last update. I'm sure Fedora and Suse probably have similar package caches somewhere.. that ay give you a little breathing room so you have some space to work..
Another good option for you might be to add a hard drive and MOVE the /home directory from /dev/hda to the new drive.