How do I block all x rated sites.

I just heard a new one advertised on the radio
I will add it here when I hear the ad again

I tried one of those blocks about 10 years back but it blocked sites where you could order things which I didn't mind because I don't buy stuff over the internet. But then I went to go to some of the sites FOR kids that also sold stuff so they couldn't get on like Crayola and Nestles fun pages.

Hopefully the blocks have improved since then.

You can't. Unfortunately there is no sure way to determine what's X-rated and what isn't. For example one WEB filter program blocked a site that discussed breast cancer because of the word "breast".

there are filtering programs that will block some sites, but nothing is absolute.

Getting on soapbox:
I have long advocated a "red-light" district on the Net. Setting up a top level domain of .xxx or .sex. Then one could easily block all sites with that domain. ICANN, the agency responsible for creating top-level domains has discussed this and has rejected the idea on the grounds that it will make it easier for people to find such sites. The other problem with this idea is there is no way to force a site to use such a domain.

I heard the commercial again
It is

SeeNoEvil - Online Adult Content Blocking Technology

I don't know anything about it.