Parental control software recommendations

[Taz]

I need to install some parental control software on a machine to ensure that inappropriate Web sites are not visited. Does anyone have any recommendations for such software?

[Edit]: Remote (Web-based) administration would be a good feature to have.

[wasabi]

Dansguardian is very very good if you're using linux or Mac (I use it as a proxy server at work - a school). Net nanny is pretty-much ok on windows given my brief experience. If you want free on widows you could download some pornsite blocklists from http://urlblacklist.com and whack it in the hosts file, though this is very crude - also it takes a while to 'bed in' urlblacklist lists as they tend to have some silly blocks in added by the paranoid..