What are the advantages and drawbacks of using OpenDNS?

I’ve been thinking about signing up for OpenDNS for a while, and a friend just told me that if I was using OpenDNS I wouldn’t have to even think of Flashback. Is that true? I thought OpenDNS was mostly for filtering web sites, which is significant issue with two 14 year old boys in my house. I never considered it as a security tool per se.

Story added 4. May 2012, content source with full text you can find at link above.