It looks like it actually includes a couple different firewall methods as default modules, here are a few from http://www.webmin.com/standard.html

BSD Firewall (only for BSD, but maybe Slackware?)
IPFilter Firewall (Solaris)
Linux Firewall (this one is iptables)
Shorewall Firewall (also iptables, requires shorewall I would imagine)

There are tons of other stuff listed on the page so check it out if you are interested. You can pretty much administer the entire Linux system from a web browser, it even includes a console of sorts. I would probably only want to limit access to trusted IP's, but that's just the paranoia in me speaking.

regards,
...aaron

Thanks for the very interesting info! Great link!

http://bookmarks.linuxquestions.org/.../tags/firewall the link on that page is what I use. Takes seconds. No gui, but you don't need one.

How reliable is this script though? does it block unwanted IPs pretty efficiently?