How do I automatically split video files into separate clips?

I imported a lot of super 8 film using iMovie. While the import worked great it didn't split the video into separate clips. I've read that iMovie does this automatically for DV tapes. Is there any OSX software out there that will detect when one clips ends and another begins and automatically split the two into separate files. I imagine it would have to compare adjacent frames and determine if the difference between the two was great enough to warrant a split.

FYI I'm looking for a simple application that will do the above without breaking the bank. I don't want to invest in a video editing suite right now.

You might find ReCut helpful.

ffmpeg, a free open source product, looks like it is working on this issue. Unfortunately, it is not complete yet.

See also this Super User question: Automatic Scene Detection

This is probably not a real answer (I do not have enough reputation to leave it as a comment on the question), but it gives a bit of information on why iMovie and other cheaper video editors split DV, but not super 8 and other analogue tapes.

DV formats encode the timestamp on the feed, and applications can read these timestamps and when a stop/start point is detected (missing time seconds) they split the video.
To split analogue formats, you must do image comparison, as you mention, detecting when the whole frame changes between frames. There are applications that do this, but I do not know of any that are in the lower price ranges.