I read about this on Mike Dipetrillo's blog. I thought it was a great post.
Ever want to setup DR but don’t have a SAN? Well, there’s several ways you can do that. The newest one is to use the EMC Celera Virtual Storage Appliance (VSA). Chad Sakac over at Virtual Geek just published the very thorough (and long) guide on how to set this up. Don’t want to use EMC for some reason? NetApp and LeftHand (now HP) have guides of their own. For NetApp go here. For LeftHand go here.