MaroonOut - how did you like SMU and UH? So far I've only visited Baylor (which was great!) and UT, thinking I might try to hit those other two before long.
If you have the chance to visit school prior to applying, you definitely should. The advantage of doing so is that you can meet with the Director of Admissions and in a subtle way, "sell" yourself to the school.I visited 6 schools a month ago - UVA, George Washington, Georgetown, American, George Mason, and University of Maryland. I think meeting the admissions officers certainly could not have hurt, and I would like to believe that it helped. I just received my acceptance from Maryland, and they're offering me a scholarship. With that said, I don't think you should fret if you can't visit schools. But if you can, by all means you should.
The thing is that there are a ton of people who meet the admissions officers. You think they're going to remember everyone that comes to visit their schools? I highly doubt it makes a difference one way or the other in terms of meeting the admissions people.