The funniest kind of e-mail is the ones that say call me back tomorrow at ... If the person asks why you didn't call back you just tell them every time you made sure about the time and it still said that it was due for tomorrow.
The same principle as the be back in 15 minutes post-stick notes... I used that trick a lot.
Them : you weren't back within 15 minutes.
Me : Have you reread the not?
Them : yes
Me : There's the reason.
Wow! That's pretty awful. Last week, I stopped to help a coworker with a technical question on my way back from the rest room. When I got back to my desk, my boss asked me why it took me 17 and a half minutes to use the rest room. I never realized before that he was timing me. It's a little creepy... (But at least he doesn't follow me...)
@sweetnsilly: Reminds me when I first started working as a clerk and we had a crusty old supervisor who took out a stop watch and timed you going to the bathroom, and if you stayed a second more than 5 minutes she would burst into the men's bathroom and bang on the cubicle door and tell you get the f*ck back to work. The good old times...