Been meaning to mention this site for a while.
Black Cab Sessions features clips of musicians who take a cab ride (in England) and play one song while in the back seat.
Musicians include Ryan Adams, Bon Iver, Death Cab for Cutie, Fleet Foxes, Richard Thompson, My Morning Jacket, Grizzly Bear and many more. (And has anyone mentioned that Death Cab's Ben Gibbard looks just like Tin House editor Rob Spillman?)
I still haven't spent much time checking out the site. But I hope to soon. Maria says the Calexico clip is pretty cool.