From the music blog Arjanwrites.com....
They're a mash up song...
"They put together Kylie's "2 Hearts," a cover version of Goldfrapp's "Strict Machine, The Killers' "Smile Like You Mean It" and The Timelord's "Doctorin The Tardis," which is based on Rob Grainer's 1963 composition of the Dr. Who television theme. To add to all the time-traveling madness, Fast Ood Rockers also included some Christmas effects and rave horns."
Listen to it here, it's pretty fun:
http://www.arjanwrites.com/arjanwrites/2007/11/listen-to-fast.html