Thanks to all for your responses and advice. To answer some of your questions, my motivation for the trip is really not much more complicated than looking for something different and challenging to do over the next year. I realize it's going to be an endurance test, but also want to focus on the simplicity involved in getting somewhere by just placing one foot in front of the other.

I'm starting from the eastern US, so I'm likely to start once the weather gets warmer here- I'm thinking to leave once the temperature breaks 70. I don't have a specific route planned. I'm tentatively planning on ending up in Portland, OR, so I should stay north for the most part. I'm also planning on bringing along a good road atlas which should help in providing direction as I move along.

I appreciate your advice on the more desolate areas of the west- I was also expecting that I would have to do a great deal of camping in areas not specifically designated as such. Should I expect problems with the authorities if I do this or are people left alone for the most part as long as you move on?