There is an app called Snapz Pro X, which, among other things, allows you to record QuickTime videos of your screen. It might be worth looking into, although I'm not sure how well it does with OpenGL applications (like BlitzMax).
Also, QuickTime Pro can convert numbered images (i.e. ScreenShot01.jpg, ScreenShot02.jpg, etc.) into a QuickTime movie if you've bought QuickTime Pro. Just choose "Open Image Sequence" from the File menu and export it back out as a movie.
Also, QuickTime Pro can convert numbered images (i.e. ScreenShot01.jpg, ScreenShot02.jpg, etc.) into a QuickTime movie if you've bought QuickTime Pro. Just choose "Open Image Sequence" from the File menu and export it back out as a movie.