Block the 6700 worst spamhosts
$ wget -q -O - http://someonewhocares.org/hosts/ | grep ^127 >> /etc/hosts
The above url contains over 6700 of the common ad websites. The command just pastes these into your /etc/hosts.
On Windows 7, the hosts file is located at C:\Windows\System32\drivers\etc\hosts
References
[Click to add or edit comments])
Please prepend comments below including a date