This firewall is really, really effective. But unlike some other ones, it is able to be turned off when i lock myself out.
The interface does not have an overwhelming number of options, which i like. simple, clear instructions make it a must-use plugin for everyone.
MOST IMPORTANTLY, however, is that WP Simple Firewall does not conflict with any other of the 30 plugins i use, or my theme.
I really like it and cant recommend it enough. Thanks!