The EnergyPod by Metronaps promises to "improve employee morale while boosting the bottom line" by encouraging powernapping at work. It's basically a jazzed-up recliner with a blast shield that provides a "semi-private acoustical and visual environment." When it's time to wake up after 20 minutes the chair starts buzzing and beating your face with lights. Gently, of course. Not so gentle is the price: $8000.
Personally, I found face-planting on my desk during class in high school to be a fairly effective way to powernap. And by powernap, I mean sleep through the entire period. Which is pretty much how my powernaps at Giz work.