Me and my boyfriend are planning a road trip for this summer. We plan to go cross country (starting in WA) and want to hit the smithonians in DC (preferably stop somewhere short of that and train in) and Missouri. I'm really excited but he is nervous about the costs. We're taking a car w/ 40 mpg and have up to 8 weeks to spend (lots of meandering hopefully). Any suggestions on routes or places to hit? Or even better on cost? We plan to camp most of the time.