If you're interested in an inexpensive, challenging, and beautiful bike tour, check out the Bicycle Tour of Colorado (
http://www.bicycletourcolo.com ). I've ridden this tour for the last 3 years (the route changes each year), and plan to return again this year.
They get about 1500 cyclists each year, with most choosing to camp out (hotel option also available). The organizers provide very good rest stops and support, and the scenery can't be beat.
For pictures of this year's tour, check out
http://www.shastasoftware.com/BTC2003/BTC0017.htm