Yakuake

Are you a Linux user? Do you use the KDE desktop? Have you tried Yakuake? I just have and it's brilliant! Here's a screenshot of my laptop with it open:

You can leave it on and open or close it by pressing F12 (or whatever key you set it to)! I don't know if I ever want to use Konsole again! Now I can press F12 to open a terminal session, or the Windows key to do a Google search with Google Desktop, or open any application with Katapult using Alt+Space.

Give Yakuake a try if it's in you distro's repositories. For all I know, it might work OK with Gnome as well.