Transforming an old PC into a super web app monster could no longer be considered an exploit with the advent of the web-based operating system gOS. This Ubuntu based OS can be freely downloaded and burnt into a LiveCD and eventually tested on any of our “worn-out” PCs.
Better still the low ram consuming gOS could be installed on the buntus (Lubuntu, Xubuntu, Kubuntu) for a better comparison and if you feel more comfortable with it, why not replace it with your Ubuntu.
On Ubuntu simply do this
sudo gedit /etc/apt/sources.list
Add the following lines to your sources.list
deb http://packages.thinkgos.com/gos/ painful main
deb-src http://packages.thinkgos.com/gos/ painful main
Now import the key;
sudo apt-key add gos_repo_key.asc
sudo aptitude update
sudo aptitude install greenos-desktop xorg
To uninstall gOS off Ubuntu do;
sudo aptitude purge greenos-desktop
via [Ubuntu Forum]