Because nobody reads the (online) manual anymore, I've collected the some of the common "keyboard" shortcuts for the Zune device and software. May this page provide you with a happier Zuning experience.
Power On, Wake (while the device is off)
Quick Sleep (while the device is on)
Full power off
Hold Back and Down
Return to the main menu
Reset / reboot (while the device is on)
Hold Back and Up
Device Recovery (reformat)
1. Hold Down and Back to power off.
2. On a 2nd generation device (Zune 4/8/80):
2. On a 1st generation device (Zune 30):
Note: Afterwards, your device will need to be attached to a PC to initialize and download the latest firmware.
Disclaimer: Use only as directed by support etc., etc.
Notice: The information here pertains to current devices with firmware version 2.3; other versions (past or future) reserve the right to change these combos.
The extra media buttons on some keyboards also work for keyboardizing stop, play, pause, next track, and previous track.
More PC keyboard shortcuts can be found on the Zune help site here.