I work on a contract basis for a professional sports car racing team, and I always share a hotel room on business travel.

However, because I travel and work with the team as a unit, I always have the same roommate - our team's data acquisition analyst. I've developed quite a good rapport and friendship over the years with him (heck, we'd better, we've spent the better part of three or four months sharing a room now since I got hired in '05). He's introduced me to great music and we've shared our computer-geek sides

The only annoying part is when he hogs the shower every morning

My employer is too small to have any sort of written policy on this, but I assume if I wanted to fork over the extra costs to have my own room I could do so (as I do for air travel.) But to me, it's not worth it, at least as long as my roommate is tolerable. I can easily see how it could be disastrous...