Looking over the Debian own harden-doc guide online, (which is a monster of a resource) as well as Debian Help’s security page gave me some excellent new ideas on how to secure Debian and Linux in general. Also today i found a netstat command with some nice switches to help you figure out what is listening on each port in an easy to read layout, -plunt:
netstat -plunt
Plus it’s fun to say, ‘plunt’. Lastly there’s a good overview of deborphan (which assists you in keeping your system clear of unneeded packages) with coverage on how to use it at Debian Adminstrator.org. But in the comments a thread talks about how it’s better to use aptitude, as this does it automatically.