I think it would be useful to have a discussion on internet filtering. Any Christian who does not use filtering is asking for trouble. Internet porn is the fastest growing reason for divorce. Unbelievable behaviors are triggered that we don't even know are lurking in our characters. 50% of men, Christians or otherwise who use the net are using porn, 40% of pastors, 29% of women...
There are several good filtering systems out there. Most are aimed at protecting children such as netnanny or cyberpatrol These are fine but they provide an over ride password which will allow the "grownup" administrator to turn it off. If the "grownup has porn issues then this will not work for them.
There are some excellent filters designed for adults (these will be fine for children as well). These systems do not provide an override password but instead if you want to remove or change it than the primary customer (your wife perhaps) would have to phone the filtering company and identify themself through security questions etc. A couple of these systems also include accountability reporting. This feature allows you to have an accountability partner who will receive email notifications if you are attempting to break through the filter to porn sites. The beauty of this is that the offender will get a phone call from their partner asking what is going on? These calls are uncomfortable and most folks try to be good so as to avoid them. take a look at wisechoice filter, covenanteyes and xxxchurch.
There are some free programs available but typically you get what you pay for.