OK, this post is more about recovering the Katapult functionality that I love. In fact, I started using KDE because of Katapult! But I digress.
In KDE4, which I recently installed there is a program called KRunner. It works exactly like Katapult, but the shortcut key is Alt + F2. This is a VERY poor shortcut; it’s a stretch to hit the Alt and F2 button at the same time. Previously I used the excellent Katapult (Alt + Space) as a launcher/calculator.
To change the shortcut:
K -> System Settings -> Keyboard & Mouse -> Keyboard Shortcuts -> KDE Component (Run Command Interface) -> Run Command.
Click Custom, and then press Alt + Space, or whatever shortcut combination you want. Click “Apply”. Voila.
Please also note that you need to prefix an “=” when typing equations, unlike Katapult; e.g.