Power naps have been shown to be a very useful tool for maintaining productivity. They are especially effective for those who are sleep deprived, but for one reason or another (studying, working, trying to pick up hot guys), need to stay awake. The optimal power nap will fill you with renewed energy for whatever task is at hand. Beyond
anecdotal testaments from such luminaries as
Winston Churchill and
Buckminister Fuller, recent studies have confirmed that the power nap has quantifiably beneficial effects on performance. Dr. Sarah Mednick reported in
Nature magazine in the July 2002 issue that allowing subjects undergoing visual tests who had been sleep-deprived a half-hour nap prevented further deterioration of test scores, and a one hour nap actually improved them.
There are two different types of power naps. Short power naps, lasting up to about a half hour, are most useful for recovering wakefulness after sleep deprivation. They're quick, they're easy. A one hour nap is better suited if you really need to recover yourself fully, because it you will go into an intense period of REM sleep, however the disadvantage is that you will wake still feeling sleepy, and will need to overcome sleep inertia before the benefits are felt. If you're seeing a connection between this and Uberman's Sleep Schedule, you're correct; the power nap is the defining backbone for the method. Caffeine will completely negate the effects of the power nap, so you'll either need to go with one or the other.
Embracing the boost to performance that permitting power naps can give, many progressive companies have recently installed 'nap rooms' where employees can catch a quick snooze to (ironically) wake themselves up. There are even some schools that allow it (better the kids sleep under the watchful eye of a moderator than at their desks in class, damn early starting times!). Hopefully the gospel of the power nap will spread further, because I personally wouldn't mind having more places to crash and catch some quick shut-eye. *yawn*