I used to work at the IBM 24-hour helpdesk in RTP. Working the evening/weekend shift there was much napping and going out for Chinese food, but there was one guy who lived in legend.

He had two fulltime jobs, one during the day and one at night. At night, he would show up at IBM with a blanket and pillow, crawl under his desk, and turn out the lights in his area. He'd take the phone under his desk in case it rang, in which case he would wake up and take the call.

We didn't have any managers there at night, but I think at least some of them must have known about it. I think he did a good job and it was hard to get good people to work the midnight - 8am shift, so they didn't say anything. But eventually upper management found out and he was fired. Too bad. I thought it was a great idea.

p.s. The coolest boss I ever had once gave me a great tip on how to sleep at work. If you have your own office (or I guess it would work in the conference room method mentioned above), lie on the floor with your feet against the closed door. That way, if someone comes looking for you it will wake you up. Also, if you do get caught lying on the floor with your feet against the door, say your back was hurting from sitting at the computer for so long so you were doing back exercises prescribed by your physical therapist. It works!