If you already use a hosts file, you just add a line like so:
127.0.0.1
www.frugalsimplicity.com
Instead of trying to translate the above link into its real IP
address, 69.72.141.161, it sends it to 127.0.0.1 localhost on your
computer, which means, in effect, it goes nowhere and the page doesn't
load.
For a good explanation of a hosts file, what it does, how to use it
and to download one that blocks the majority of problem sites, see:
http://www.mvps.org/winhelp2002/hosts.htm