Pretty sure this is a "duh" question, but is there any method out there (or cameras) that allow speeding up the capturing of images so that regular playback is actually slo-mo, like they do with film?
You might be able to use something like this. You have to capture direct through firewire or USB 2.0 to a laptop or workstation. You can get very high resolution and frame rates with some of these devices. I haven't tried any but I guess they are only a few hundred dollars.