A couple of days ago, VMware released an interesting primer on virtualization, that gives a good introduction on a topic that is kinda "foggy" for most non-deeply-technical people. In the paper is given a nice overview of virtualization techniques for intel x86 architecture, along with an high level survey of the state of virtualization technology.

Definetely a recommended reading for anyone willing to know more about virtualization, but not only... Fetch it here ("http://www.vmware.com/resources/techresources/1008").
http://ivory.vnunet.com/company-logos/vmware-logo/medium.jpg ("http://ivory.vnunet.com/company-logos/vmware-logo/medium.jpg")

http://reversingitout.blogspot.com/2007/11/interesting-primer-on-virtualization.html