I've been looking into amtrak a little, it looks like I can get a ticket from Cleveland to Denver (with a sleeper car from Chicago to Denver) for about the price of a flight. The only inconvenience is that I have to return my rental car in Cleveland by about 6PM and the train leaves at about 3AM from a station in the middle of downtown. Other than hanging out at a train station for half the night (which isn't going to happen), I would have to grab a hotel in the evening and check out very early to get a cab or limo to the train station. That's not a big deal, but it will require a little planning. I might give the train a try, it can't possibly suck as much as flying.