I have a movie of me skydiving, but the disk is starting to get scratchy. I was wondering how I can copy this to my hard-drive, so I can play it whenever I want. I tried the disk utility and copy the disk to an image, but that only copied the files and folders, thus not making it playable as a videofile.
My presumption is that when you burned the DVD using iMovie - it was encoded within a VIDEO_TS folder and you will need some software to move the video and sound files (which are hidden and obscured on the filesystem) back into a format that can be played on your Mac and/or burned back to a fresh optical drive.
Depending on the version of software that wrote the DVD to disc, you might be able to locate the raw video files (or find them on a backup). Barring that, using Disk Utility to simply clone the volume onto a new drive isn't a good choice, but I've had great luck with programs like the little app factory's RipIt.