Ronald van Engelen has kindly set up a PPA for Guimup. This PPA currently publishes packages for Ubuntu Quantal and Precise.
To add it to your system’s Software Sources open a terminal and enter the follwing:
sudo add-apt-repository ppa:guimup/trunk
Next update your system:
sudo apt-get update
Finally install Guimup with a program like Packagekit or with this command:
sudo apt-get install guimup