I bet its been suggested before but another vote can't hurt.
1) Auto-update of Ad-Watch sistes.txt - with auto restart (if still needed depending on implementation).
2) White list file maintained by user that gets merged (or should that be de-merged) from the sites.txt file when activated. As any white list is a target for the black hats this white list should be suitably protected.
Whaddysay
Regards.
Chas.