I have a 450GB NAS attached to my home network that stores things like music, pictures, and other assorted stuff. I am trying to think of a good method to back it up. I could get an external hard drive and periodically copy stuff there, but I would still store that in my house, and being the geek that I am I wouldn't mind storing something in my lock box at the bank. CD's are out of the question.

Any suggestions? I wouldn't mind paying a little money, but I don't want to break the bank as this is just for personal use.