Boulder is a town in Colorado. It is a good town for travelers: there are programs that cater to the poor, such as free meals, and you can easily camp in the foothills and canyons just west of town. Camping in town is a bit more difficult but probably easier than most places as far as civilian and police response. There is a community of homebums and street kids; many will gladly help you if you ask.
Hitchhiking out to Denver
You can walk or take a bus. Follow Broadway in southern direction untill you find Baseline Rd on your left. Take Baseline Rd untill the highway. There is a gasstation just before the ramp as well. On the shouder, it took me less then 5 minutes to get a ride to Denver. You can also catch a fairly quick ride south to Golden on Route 93.
One should consider the University playgrounds and surroundings.