How to run a script constantly in background under linux

I have a perl script which runs a mini webserver allowing me to do various things. I'd like to have this script run when the machine starts up, and constantly run in the background.

How should I achieve this? I want the script to regardless of whether anyone is logged in or not, so I can't put it in any bash-related files.

I'm using Debian, if that affects things (which it probably will)

You will want to use the init facility (/etc/rc.d) or daemontools. If it's a recent version of Debian, you can use Upstart.