Best way to travel the Western U.S.?

Because the Western United States is so large, what is the best way to navigate through it without loosing too much time by traveling?

(We are from The top of Florida, but we will be in New Orleans Louisiana for New Orleans, and after that we would like to travel to the west - Texas, New Mexico, Arizona, and California. The farthest location we would like to visit is San Francisco California.)

We have considered driving, but that would be so far to drive.

We are not opposed to traveling by train or plane, however we would like to drive through Texas at the least.

Traveling thru Texas will take about 3 -4 days by car. If you really want to see the states, go by Rail. It will take longer but you will see some wonderful country. The best part about train travel is you don't have to deal with traffic and you can move about the train with no problems. Be sure that you reserve a cabin / sleeper that way you can rest when you want. Here's a link:
http://www.amtrak.com/servlet/ContentServer?pagename=Amtrak/HomePage
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