I use OpenDNS which is far from perfect, as you need to install it on your home router and it doesn’t filter if you go to a coffee shop or something.
I’m looking in to getting TechLoq. It’s not expensive, and it has content filtering, so it checks the words and pictures on a webpage before serving it. It also does not have spyware. I frankly don’t want all my passwords and emails available to some anonymous guy in an office somewhere, which a lot of filters do.