I have a couple of experiences with this.

Since I have been out, I think I have shared a room 3 times with a co-worker. Twice, I was sharing with a gay co-worker when we both selected each other. Once, it was with a straight guy, but this was a guy who has known me for years, and who knows my bf. No risk there.

Yes, it is not horribly professional, but these trips were all "reward" trips for the whole organization, and everyone was sharing a room. We are having another trip next month (Club Med, Cancun), and I am now at the level where I do not have to share, although I would be accomodating if I did not have to share a bed.

When my boyfriend goes to his conferences, he has a female friend who is his regular roommate. They have had such a great time that another (attractive) straight male friend has asked to become the third person in the room.