In a discussion about online storage in a Linux mailing list I read, there was a great comment about how to get more efficient backups than pushing hundreds of gigabytes of data to the web:

I think just backing up to /dev/null is probably cheaper and quite a bit faster, since it will all be local data transfer and not over the internet.  /dev/null seems to have quite a bit of space in it, from what I can tell.  Haven’t tested my backups yet, though.  Probably ought to do that some time.  I believe that /dev/random is the proper read device for that.  They say restores take a while, but I’m sure I can live with that.

Okay, I admit, you have to know what Linux device files are to get the joke, but trust me that if you do, it’s really funny.