If you are 21, there are slot machines in the airport. I was stuck at that airport before I was 21, and just waited.. nothing great.
Another time, same flight, going to San Diego, it turned into 5 hour wait due to storm somewhere, and I took a shuttle and then a taxi back. I went to MGM (5 minutes away) but wouldn't risk going. Since you subract your time to board, and Security, and ect ect you may cut it close.
You can go to bar too in airport, if 21