Ant, frankly I am not sure it is realistic to stand over the kids' shoulders every second they are using the computer. Computers are now used for things such as homework, and I don't think it's necessary to be there every second they are doing that. There is, of course, very decent software to block adult sites. It won't filter everything, and if a kid really wants to see something they will, but it does protect children from bumping into something very inappropriate - nowadays, sometimes you accidentally drop a letter from an address of a web site and - presto! - you have a dozen porn pop-ups. I would, of course, urge parents to install blocking software - sometimes those pop-up sites are ones that are not appropriate even for an accidental glance, and those can come up no matter what you do. Sometimes it gets funny -one time in college we were building an internet browser in a .NET class, a professor missed 1 letter in a URL, and suddenly the whole class was treated to an array of porn!