I stopped using tape for backups about 5 years ago, and just went to hard disks for back up storage. Before that I tried using CD and DVD for backup, but too much swapping disks and very unreliable after just 5 years.
Now I use a local raid server for backup. (note: I am not *depending* on raid technology for backup, I am backing up my main PC to a raid server). Since I am running linux, I use automated scripts to make back ups of important work for me on a regular basis. The raid server is also my time machine server for my OS X desktop.
For anything offsite, I use a USB drive now and ship that away, or the cloud like Dropbox if it's not excessive. I can encrypt stuff and put it there safely without worry.