Tim Montee has posted a video slideshow of Lenard Roach's long, 20+ hour trip from Kansas City to Las Vegas and back.
That beats my road trip when I went to california extreme (2002?) in san francisco. We popped down to las vegas for the day, dropping in to los angeles for an hour as it was so close.
Everyone drives so slowly in America though, which is weird as you have some lovely open roads. In the UK, we'd have to slow down for the flux capacitor to kick in at 88mph.