This is cool: Yakuake, a KDE console application. Instead of opening just another application that lives in your task bar, it hides itself, to be shown when you press F12 (or a key you assign to it yourself). It drops down from the top when you press the key, let's you do the work, and rolls up again when you're done. Quite nifty!
the Yakuake Homepage you link to it obsolete. The old maintainer cannot be reached to take it offline.
There will be a new homepage at http://yakuake.kde.org/ and until then there is http://www.kde-apps.org/content/show.php?content=29153
For further questions please visit #yakuake on freenode.