blocking things on the internet

[Margies3]

I have a 13 year old son who has been known to go to areas of the internet where he should not be (nothing pornographic, just websites that I don't approve of).

His friend's mother said that her husband installed a program called 'Canine' on their computer yesterday to keep her son from going to unauthorized sites. I can't find any more info on that.

So my question for all of you is: have you ever had experience with using a software to keep parental controls on your computer? If so, what have you used and what have you liked or not liked about it?

Thanks for your help.