When I switched to Linux, one of the reasons I adopted KDE as my desktop environment was the krunner launcher. Hit the Alt-F2 hotkey (or remap it to Alt-Space or the “My Favorites” button on a Microsoft Natural 4000 keyboard) to open the krunner interface, and start typing the name of the app you want to launch. Or the file you want to open in its default app. Or the folder you want to explore. Or the arithmetic you want to quickly calculate. Or… you get the idea. Krunner is incredibly powerful and much faster than moving a mouse, clicking on a menu button, moving down, moving over, and clicking.
But just the other day I discovered something even better about krunner. If no window has focus, just start typing the app name, file name, etc. and krunner will open automatically. No hotkey required. Think of the hundreds of millliseconds I can save multiple times a day….
Okay, not the most amazing lifehack ever, but still cool.