After Captain Hammer jumps on top of the van that Dr. Horrible is attempting to hijack, he punches and destroys the device Dr. Horrible was using to remotely control the van. The fist punching the device is Joss Whedon's.
The phone that Dr. Horrible uses for the Van Tracking Device is an iPhone with AT&T as the carrier. The time on the phone was also 4:57pm and the "fake" app he was using was called 'Horrible Van Remote'.