securing Ubuntu and firewall

[H.S.]

Hi,

Just wondering, what application is usually used to configure iptables
to secure a Ubuntu box? I am currently looking for a GUI firewall
application to introduce to a friend who has converted from Windows to
Ubuntu on his home machine, but who is not a typical Windows ignorant
user (considering that he knows vi!).

I have so far found firestarter. Comments and suggestions are welcome.

->HS