Jimmy Fallon Recruits Jake Gyllenhaal for 'Hedgehog Doing Karate' Song (VIDEO)

We've seen a lot of Jake Gyllenhaal the last couple weeks, thanks to oodles of press for 'Prince of Persia.' At least Jimmy Fallon was good enough to employ him in a different way -- no standard couch confab -- on 'Late Night' (weeknights, 12:37AM ET on NBC).

The actor joined Fallon to perform 'Hedgehog Doing Karate: The American Idol Song,' a little ditty Fallon wrote about the 'Idol' finale and "things that don't exist."

The host started things off, then was joined in song (and dance) by Gyllenhaal, wearing a yellow jumpsuit. The duo carried their moves into the studio audience, singing very close to one lucky (but uncomfortable) young woman.