I heard about this on the news.
Bicyclists in the Illini 4000 are bicycling 4000 miles from NYC to San Francisco. Of course they're not taking the most direct route from NY to CA since the I-80 corridor is only 3,000 miles, and they'd have to bicycle entirely on non-interstate highways.
http://illini4000.org/route/ (http://illini4000.org/route/)