Did it once, with 2ci, 2cb and mdma. I wouldn't go out of my way to do it again, but if I was to be in LV for some reason, I would not hesitate to try out low-to-moderate LSD or iprocin there -- but I actually think 2cp would be perfect -- LV would definitely benefit from 2cp's stimulation & time distortion. I'd bring a little valium as well.
Tripping out really elevated LV for me. Like people said upthread, it generally was a "participant observer" trip. One night some friends and I just wandered up and down the strip. I felt pretty safe because it was clear if I acted intoxicated everyone was expecting me to be drunk, and most of the other people were way more outrageous (the AVN conference was going on). The more dated and dank the casino, the more we loved it. NY, NY was the big winner with a really amazing vintage video game arcade in "Coney Island" (a damp, carpeted nook above the main floor). I also highly recommend the stratosphere and circus circus, despite the fact when we went the rotating bar from F&LiLV was decommissioned.
Personally I love heart of darkness trips on occasion. I had a really great time confronting the decaying underbelly of the American dream. If you are someone who also enjoys tripping in places like Times Square or downtown Detroit, you will probbaly get a kick out of Las Vegas.