Bike and Build is totally legit. The type of people who participate in the organization are passionate, friendly, ambitious, and adventurous (and I'm not just saying that 'cause I'm one of them ).

I rode for the organization in 2007 and it was the best summer of my life. I actually had never ridden a bicycle more than 30 miles cumulative in my life before that trip, and I'm totally hooked on cycling now.