My best friend is getting married to a man she works with, so it does work out sometimes. I would have reservations about getting involved with a coworker, esp if I work closely with him everyday. I guess you can't help who you fall in love with though. I think if I was to get serious with a coworker, one of us would eventually have to find another job.
Luckily for me, my office is mostly female and the men who are here are older and married.