Normally it would be expected that if you were caught asleep at your desk you would be disciplined, possibly even fired. According to recent studies having a nap at work might actually be productive, not just to give you a physical boost either.
Studies have also shown that taking a nap will improve perceptual and motor skills, reaction time and alertness. Some companies such as Google provide nap rooms - with a recent 10% pay increase across the board getting paid even more to nap sounds very appealing!
Best time to nap is sometime between 1 pm and 3 pm and not for more than 30 minutes. I have certainly found on occasion that a quick 40 winks can be a productive use of my time, versus trying to pull through an increasingly tiring day and becoming less productive.
Speaking of which, I have been spending quite some post nap time looking at product and service offerings for 2011 and will be making some announcements soon. In the meantime fluff up that pillow and get energized!