Setting up OpenDNS On Ubuntu
Via: How To Setup OpenDNS On Ubuntu : Ubuntu Tutorials : Breezy – Dapper – Edgy – Feisty
I just switched my DNS to OpenDNS based on the tutorial and the instructions on the OpenDNS site which has Ubuntu specific instructions. There are a few good reasons to do this, first being it’s safer. In theory it’s faster too but it’s too soon to tell.
Microwave Biscuit 
It seems a good deal faster to me, but if your ISP already had a really reliable DNS you might not notice much more of a difference.