SpongeBob as Jules Winnfield and Squidward as Vincent Vega. I can only assume that Mr. Krabs would play Marsellus Wallace. (CtrIAltDeI via a tip from John at The Zeray Gazette)
Edit: Clearly I'm an idiot. That is Mr. Krabs tied up, so I have no idea who would be playing Marsellus Wallace. Plankton?
Previously on Popped Culture...
Birth Of Squidward
Extra Pulp Fiction
SpongeBob's Got Big Balls