Do you use the terminal a lot in Linux? With only Compiz Fusion and Gnome-Terminal you can have a transparent terminal that looks like it is part of your desktop. (See the screenshot at the end of this post.) I found the idea for this over at Ubuntu Unleashed, my instructions here are slightly different.
You need to create a new gnome-terminal profile for the transparent terminal. Create a new profile in Edit>Profiles>New called trans. Edit the new profile and set these options: