Secure Ubuntu?

[David Teague]

An article I just read talks about hardening Linux. Here is a link
http://www-128.ibm.com/developerworks/linux/library/l-seclnx3/?ca=dgr-lnxw63SecLinP3

In this article they state that "these steps are generally referred to as
hardening Linux:
  a.. Securing the boot process
  b.. Securing services and daemons
  c.. Securing local filesystems
  d.. Enforcing quotas and limits
  e.. Enabling Mandatory Access Control
  f.. Updating and adding security patches
Is any of this already done in Ubuntu?
How much of this is necessary?
Is all (or any) of this desirable on a single person's desk top?

I don't think all of it is even desirable for a desktop system run by just
one person, but I will be connected to the internet via high speed
connection so I solicit opinions on the matter.

I was concerned about not seeing firewalls here. I see this under
securing services and daemons.

Quotas on machines at my University were annoying, but I suspect
that would be a big step towards security..

David Teague,  http://cs.wcu.edu/~dbt
Advocating Free Software and Double Bass tuned in fifths
www.dennismasuzzo.com;  www.silviodallatorre.com
www.joelquarrington.com/;  For information on Red  Mitchell,
http://home.teleport.com/~mimuma/;  www.larryholloway.com