YaKuake

Yakuake (Yet Another Kuake) is a KDE terminal emulator. Its design was inspired from consoles in computer games such as Quake which slide down from the top of the screen when a key is pressed, and slide back up when the key is pressed again.

Running Yakuake is faster than launching a new terminal with a keyboard shortcut because the program is already loaded into memory, and so can be useful to people who frequently find themselves opening and closing terminals for odd tasks.