Completely unrelated to virtualization but I just have to get this out:
The Barracuda Networks Spam Firewall rocks ! 
We have done a trial of a week and cought 12% more spam than we did with our old solution (SpamAssassin + MailScanner + MailWatch) which required more and more manual configuration and tweaking of detection rules. Although the Barracuda is still partly a SpamAssassin implementation they have reworked the Bayesian system among other thin
gs.
We went to full production last Tuesday and with some more training of the Bayesian we are now at a whopping 18% increase in spamdetection.
The units have performed flawlessly so far (in active-active cluster) and we got to ditch our old SMTP servers as it does outgoing and relaying as well. With the new firmware it even does outgoing spam checking. It just sweet. And price-performance is a no brainer as we can depreciate them over three year.
Documenting a virtualization project 