As I am sure you are all well aware one of the ways that Microsoft makes our software available for testing is through the use of trials.  Here is a list of the current trials i would recommend using and the links to download each of them. 

Windows 7 Enterprise 90-day Trial            

http://go.microsoft.com/?linkid=9701662

Download the Windows Server 2008 R2 Trial Software     

http://go.microsoft.com/?linkid=9701666

Evaluate Forefront Server Security Management Console today    

http://go.microsoft.com/?linkid=9701670

Download Microsoft System Center Essentials 2010 Beta Today    

http://go.microsoft.com/?linkid=9701674

Evaluate System Center Virtual Machine Manager 2008 R2 today  

http://go.microsoft.com/?linkid=9701678

Evaluate Windows HPC Server 2008         

http://go.microsoft.com/?linkid=9701682

Of course if you are interested in pushing your test and trial machines to another level you could also Sign up for the TechNet Plus Subscription using the discount code TNITE02 and save $97 off the regular price of $349. 

Have fun Trying out the latest and greatest stuff!