Best way to compress my files

I have a nice work flow of shooting HD footage on a P2 card and then immediately bring the files into my computer using Final Cut Pro X. That converts the P2 to MOV files which play real nice. I want to create a backup of the files but the MOV files are huge. What do you recommend? I think converting each file to MP4 would take too long, right?

I read that I could create a DMG file. Does anybody else do this? What do you recommend?

Archiving onto a hard drive isn't an option. I'm looking to archive on a physical medium either blu-ray discs, DVDs or CDs. Thanks,