Adult Site Blocking (No Software Needed)

The installation is very simple.  You follow the instructions outlined on the OpenDNS website  to change the DNS settings on your computer:  (You  can also do this for your home router)

Then you need to create an account at OpenDNS and configure your blocking.  You have a small number of categories to choose from.  That’s basically it for installation.  What’s really impressive about OpenDNS filtering is the speed.  I didn’t notice any difference at all in Internet access.  That’s because OpenDNS relies on filtering at the Domain Name Server (DNS) , rather than on your computer.
Next I decided to test the filtering to see how effective it was.  I configured OpenDNS as shown to block only Pornography and Sexuality sites.

I then used Google, Yahoo! and Live to put together several searches for pornographic material, and after removing dead links, generated a sample of 100.   OpenDNS only missed four of those sites for an underblocking rating of 96% — among the highest scores I’ve seen in my collection of filter effectiveness tests.    I then tried a sample of 25 sexual education and lingerie sites, and found none of them were blocked by OpenDNS.  After two weeks of use by everyone in my family, so far we haven’t encountered a wrongly blocked site.  The high-quality filtering is provided by St. Bernard, which has been in the filtering business for about 10 years, and it shows.
I tried to get around the filter by using an unfiltered Google image search.  OpenDNS let me enter “porn” into Google images, and brought up a screen full of porn thumbnail images.  So it’s crucial that your children use search engines that have you have preconfigured to filter adult content in addition to using OpenDNS for it to be really effective.
Another downside to OpenDNS is its vulnerability to more knowlegable users, as CNET’s Michael Horowitz points out:

"The bad news here is that I can’t see how this blocking can be enforced. A knowledgeable computer user can simply change the DNS servers used by the operating system."

Remember how easy it was to set up?  A computer savvy teen can undo it just as easily, so if your child is a teenager, you either want a more robust solution or to buy some more tools to look down your browser and operating system.
Update: Most home routers allow you to set OpenDNS in your router, which you can password protect.  OpenDNS describes this here.