Much like coroners, undertakers, or emergency room doctors who develop a macabre sense of humor as a coping mechanism, the people on my current project at work have developed a similarly dark sense of humor relating to our undertaking (pun intended).
Things aren't as bad as I make them sound, but we've had our share of setbacks and snafus. So when all is going to shit, and you have to finish a software demo in time for a make-it-or-break-it trade show, a little dark humor helps to keep you sane.