Guide to cheap traveling in USA
Plane, train or bus
This depends on the distance. Believe it or not, the cheapest way to get from let's say New York City to Los Angeles is by plane. You can get the cheapest plane ticket through statravel.com and for around $150 (roughly) you can get from east to west coast, which is three thousand miles away. I once took a plane from L.A. to N.Y.C. for only $120 one way. And it was middle of August! How cool is that?
However, if you're traveling from, say Las Vegas to Los Angeles (or other way around), take a bus. You can buy a ticket at gotobus.com and it will only cost you $20 (precisely). It is the cheapest two-hundred-thirty-mile ride and it lasts for about five hours.
Those who like to look through the window while traveling and say that traveling by train is more scenic than by plane - you're right. However, not only is it more expensive and longer ride (transcontinental train ride takes days), it is also a much more uncomfortable experience and it takes a real adventurer to go on such a ride. Besides, who says you can't see nothing from a plane window? When I took the flight from L.A. I saw the desert, the sand dunes, ghost towns, everything. From afar though, but I still got a glance of it.
The only uncomfortable thing that can happen to you when traveling by plane is the TSA agents. They can be rude and if you're being patted down, keep an eye on your belongings! I had some of my stuff snatched by an agent when I wasn't looking. He kept talking to me trying to show me how friendly he is, but in the meantime...
So, don't be afraid, take a ride on the plane and enjoy the sky, the clouds, the sunset, sunrise, the desert and mountains beneath you and the thought of a hundred and something dollars well spent.