Ah. That is a good idea.
If you don't mind the space (it is kind of large without transcoding for the moment)...I'm using this to backup my DVDs and Blu-Rays to external hard drives:
http://www.makemkv.com it is really a blessing, and based mostly on open source projects that are already available.
Transcoding is in the works, so hopefully if you wanted to compress 200 movies down to 4 gigs each, you would be able to put them all on a 1TB external and take them with you wherever you wanted. ; )