If you want to keep the quality of the footage don't use video copmpression like mp2 or divx since it will loose a lot of the original quality and make it hard to recover the footage in a format you can edit. Turning a divx or mp2 back into avi can take some time and never edits as well.

I still think the Winrar works the best and can save you 30% with no discernable loss. Splitting the file lengths this way is also a huge bonus. A lot of my video editor friends think this is the best way to archive and still have the quality of the original. I just took a 364 meg dv-avi and comressed it to 264 meg using winrar. About 30%.

DVD storage is a lot cheaper than hard drives but takes more work. If you need to watch labor costs then hard drives might still be the best. Hard drives may also last longer if you don't use it but if you use the hard drive a lot and it eventually crashes then a whole big bunch of your stuff is gone!