You need to know very little about How The Web Works™ to know that this can be a good thing.

DNS is where your computer takes a name like www.livejournal.com and turns it into a number that is used to route your computer to the right webserver.

OpenDNS doesn’t just give you the correct address for a website. It maintains a list of Phishing websites and redirects these to a safe page warning you about the site you were about to visit.

Of additional interest to me for its use at my work (and to parents who’s kids have access to the Internet) is that they don’t just categorise phishing websites, but they also have categories of adult and mature sites you can bar if you want (once you’ve signed up)

Took me a few minutes to setup (a little extra poking required at work, naturally). Very unintrusive – no software to install, just a couple of settings to change and they have lots of help pages on how to do that.