Years ago I read a book:
http://www.amazon.com/Case-Mars-Plan-Settle-Planet/dp/0684835509/ref=pd_bbs_1?ie=UTF8&s=books&qid=1235827394&sr=8-1
that argued a manned Mars mission was possible with Saturn V technology, all it required was the political will.
While I've never been a great fan of JFK the whole
"We choose to go to the moon. We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win, and the others, too". is quite inspirational and perhaps what the country (& Western World) needs, rather than the pessimistic, introspective timidity currently infesting our culture.