I recently watched the movie Saint John of Las Vegas. Based on the title and description of the movie, I was expecting to see some good Las Vegas scenes. I was wrong. The majority of the movie takes places outside of Vegas, and the little Vegas there is - isn't very exciting.
A fairly major plot point involves the main character buying lottery tickets in Las Vegas. Unless there was a recent law change I don't know about, lottery tickets aren't sold in Nevada. While most of the audience probably wouldn't notice or care, this mistake kind of took me out of the movie. I also found it a little strange that someone in Las Vegas would use lottery tickets as his game of choice. Seeing John at a craps table would have been a lot more interesting.
If you're planning on watching Saint John of Las Vegas for the Vegas scenes, you might want to skip it.