You listed 2 different commercial web filter programs:
Net Nanny and Cyber Patrol.
Both use lists of blocked web sites.
The problem with nearly ALL filtering solutions is the changing nature of the Internet.
New web sites with content you might wish to block pop up every day.
Other filters are so restrictive that legitimate scholastic research cannot be completed.
The "BEST" solution is to have the PC with Internet connectivity out in the open where everyone can see where the user is on the web.
Another option, is the trust approach.
Create a written contract between you and your children detailing allowable Internet usage.
If you cannot trust your family to use the Internet responsibly, what happens when they are away from home?
Another option in some areas is Christian ISPs.
What these providers do, is limit access to only allowed sites. Any new site needs to be checked out before it gets added to the allowed list.
Here are some web sites of interest:
http://www.cyberpatrol.com/
http://www.cybersitter.com/
http://www.2watch.com/
http://www.bluehighways.com/tifap/
http://www.internet-filters.net/
http://www.hedgebuilders.com/
Chas