As soon as you start writing code for your own business, backup is a relevant question.
Since OS X Apple always came with decent freeware solutions that could be used with external firewire drives for example. Time Capsule is a logical (and great) successor.
But what about linux and windows? At work I use linux and we backup with ibms tivoli software. This is crap of course, because replay of a crashed or exchanged hd requires installation of a linux system first in order to access the backup. After that the data has to be moved bit by bit and apps have to be re-installed one by one.
As long as I used windows (until 2000), it was even worse.
(sidenote: the degree with which an os is called professional is reverse to its backup capabilities. This strikes me since ever!).
How does everybody backup their macs, linux boxes or windows systems?
Yes, I like eating dogfood. :-)