Normally I use lzx to make drive backups. Compression just seems to take a while. For that matter, I guess I could just use lha or lzx without compression to make a single-file backup.
Good questions on the alternative file systems, though. I use ntbackup extensively on Windows systems -- it works very well considering. I'd like to have something of that nature. I've also been thinking of ditching the Zip drive and putting a Travan or DAT drive in its place. Fun stuff to play with, I think.