back when we manually filtered I looked at WE-BLOCKER as a client side
solution, and passed on it in favor of an edge product.
free but doesnt work with win7 though
they suggest (for families with winV or win7)
"Check to see if Internet Explorer's content filtering settings will work instead."
not sure what they mean there, but IE used to have a voluntary ratings
system built in (PICS if I recall) not sure if that is still an option.