best portable storage method for 50-100gb folder ???

Best cost-effective portable media (like CD but obviously needing more capacity) to save 50gb to 100gb backup archive folder ?

Or better yet, how to best reduce size of 50-100gb backup folder (ie like zip file) to a more more cost-effective storage size ?

 

If it is that large, I'd put it on an external hard drive.

 

Thank you for the reply.
Do have on EHD, just wondering if there was anything more portable.
From what I can see, by browsing the web, there doesnt seem to be any hardware at a reasonable cost... so wondering, is there is any way to dramatically compress the folder full of files ?
Or, guess I can just transport EHDs.

 

I have personally built my external drives and I've used 2.5" laptop drives for all of 'em. They're really small, and don't require an external power source (they're powered by the USB port). I have an 80gb, a 100gb, and a 250gb. And portable is what they're all about. Each drive is about the size of a deck of cards, maybe a bit larger, and it easily fits in your pocket....
:-D