Blocking ALL adult website access to my computer

Hi guys, some time ago i came across a program which once installed blocked access to a large list of pre-programmed adult websites & gave you the option of adding more sites to block that weren't on the list. For the life of me I cannot remember the name of it.
What I want to do is block adult (****) websites from our computer completely - not just through safari. I dont want to give anyone the option of accessing this content via Firefox or any other browser. I contacted my ISP some time ago to ask if they could block access to out house but they said they couldn't.
Ive begun the task of googling it but thought I would ask if anyone knew of anything specific.
thanks