Reference Article: http://edpflager.com/?p=2322
1) Create a script which cd's into your pentaho install directory.
- cd /usr/local/bin/pentaho
2) Move the script to your desktop folder and change permissions accordingly (chmod 755)
3) Right Click -> Properties -> change Icon (selecting the spoon.png icon from your pentaho install directory.
4) Drag the desktop script to the quick launch task bar to create a new application launcher.
5) Modify icon by following step 3 for the application launcher script.