Yeah, I'm with Jeff....I think it would be a blast to play in front of a crowd, if it were a pro-am situation so I wouldn't care what the crowd thinks when I hit a few bad shots. Just so long as I don't play with Tiger or Phil, as I'm sure they'd probably hit before me most of the time, so when I'm trying to hit I've got several thousand people trying to move into position to watch his next shot. I can deal with distractions, but that would definitely be a new experience I'm not so sure about...
To be honest my biggest adjustment would be on a long teebox if the crowd was lining it all the way down I might get a little nervous about the people toward the front and might feel like I needed to aim exactly between them even if that didn't really line up with where I wanted to play my shot. Or if I drove offline outside the ropes into one of those situations where the marshals have to clear out the people. Maybe it is just how it looks on TV, but sometimes it looks like those pros are hitting down an awfully narrow tunnel of people. Probably not a issue for me since they wouldn't care enough about my shot to want to be close to it, but if for some reason they tried to do that to me I'd announce loudly, "hey, I'm not a pro you guys, you will want to give me a lot more room if you value your skulls!"
I've always thought reaction to being watched depends almost entirely on what you feel like the expectation of the watcher is. If you tee it up on the tips of a tough course, it can sometimes be a bit nerve wracking with an audience because I feel like if I hit a crappy shot it looks like I don't belong there. If I teed it up on the regular tees I could have hundreds of people watching and not give a damn, because I'd feel like my audience's expectation for me, some random guy they don't know, is much less when I'm playing from the tees most everyone use.