BoxWave is another company getting slowly in the Zune accessories family. They released two invisible screen protectors, "Crystal" and "Anti-Glare" to protect Zune's screen from scratches...
With over 99% visual transparency, ClearTouch Crystal™ is the absolute clearest screen protection available for the Microsoft Zune. The ClearTouch Crystal™ screen protector is designed for the Microsoft Zune user who demands the ultimate in uninhibited clarity.
Check the photos below with the screen protector on a window:
The Anti-Glare screen protector makes it also easier to view Zune's screen. (This is not for you if you'd like to use Zune as a mirror!).
Cleartouch protectors can be easily applied and removed. They can be even washed to removed dust and used again.
links: Crystal screen protector | Anti-Glare screen protector