Have you heard about Hector the Dolphin

Hector's World Safety Button™. This button is a child-activated safety tool which children can use if something on-screen upsets or worries them when using the internet.

The Hector's World Safety Button™ is a simple executable file which you can download here for free. The file installs a swimming Hector's World™ character in the upper right-hand corner of the computer screen. A child can just click on Hector (or one of his friends) who then covers the screen with a beautiful underwater scene and gives the child a positive written message for clicking on the character, while encouraging them to get adult help.

If you go onto the netsafe web page which is www.netsafe.org.nz you can download Hector the dolphin for your home computers, they are only available on PC computers though.