The geniuses from Monster and Friends have created an iPhone application which can record video up to 45 frames per second. They are still working in the final version, but to give you a taste they have published Drunknbass, a beta which records 5 seconds of video at 10 fps with a resolution of 2 megapixels. I've tested and it works perfectly. It doesn't have any interface, so you just download it, put it in your iPhone's Applications folder, click on the button and it will start recording. (less info)