Tor Browser Bundle is a set of tools that lets you access Tor network. It includes a Firefox browser configured to access internet through Tor. This can be used to open websites that are blocked in the school or the country that you are living. Also, the websites do not get much information about the person visiting them. This package includes a program called Vidalia that makes the connection to Tor. It can be configured to use a proxy server too. This is a portable application and doesn't need to be installed.