I forgot his name but read the book. Actually, I posted awhile ago (after the Columbia disaster) that one of the best justifications for an international space effort would be "Spaceguard" as described in Arthur C. Clarke's "Rendesvous with Rama". Actually, it's nicely findable with Google, so here it is:
Actually, between LEAP, SOHO, Catalina SkySyrvey, and a variety of other systemic sky surveys, SPaceGuard is practically here.
I remember reading an article about how a NASA geek used the finder scope on a defunct satellite to conduct some cool astronomy work. What I don't understand is why we don't do something like equipping the GPS satellites with 10" scopes. They already have a very accurate atomic clock, you could probably do some "virtual lens" work with these craft to look around the sky and find these rocks.