Caffeine power nap

All right, as a college student and coffee fan, I am always trying to adjust for a slightly erratic sleep schedule, and I read about this caffeine nap somewhere else online and recommend it. Basically, you make yourself some coffee (I make a big mug's worth, about 3 cups), drink it, and then take a 15-20 minute nap. During this time the coffee's going through your system, specifically your GI tract I think, and so when you wake up you not only have a nap boost, but a caffeine boost as well. It works for me, as I feel good waking up from one, and would be interested to know if anyone else has tried this and if it works for them as well.