Here's a picture of my highly customized Frankenboard.
It's got 10 distinct modifier keys (including a working APL key).
My favorite custom key isn't shown in this picture.
The top right key on the NumPad now says "Quindar PTT" (for Push-To-Talk).
When depressed, it un-mutes my Mic and plays the NASA Quindar in-tone (2525 Hz for 250 ms).
When released, it mutes my mic and plays the Quindar out-tone (2475 Hz for 250 ms).
Every web meeting feels like Mission Control:
"[In-tone] Mission Control, you're in the mud. Try switching S band to Omni Bravo. Over. [Out-tone]"
"[In-tone] Roger that, Houston. I've got you 5x5. You're in the pipe. Over. [Out-tone]"
Drives my co-workers crazy!