I did it in '05 in one day, on a half hour of sleep(I was working swing shift the night before). It took me just over 16 hours with 13 of that actual riding and 3 hours for breaks and 15 minute naps.
I road a 1974 Schwinn Le Tour road bike, with some parts upgrades from the swap meet and e-bay. It weights 28 pounds after I stripped it of the fenders and racks that I normally use for commuting. Total cost was about $150. I had 1 1/4" tires on it(1.25= 32mm) and I passed a guy leading a paceline on an Orbea while in the rolling hills.(Ha! See, steel is real.)