If you were not aware Microsoft has quite a few vhd's (virtual hard drive) available for people to download so you can try out new technologies without affecting your home or business environment. In order to run these vhd's you will need Microsoft Virtual PC 2007 or Virtual Server 2005.
The Internet Explorer team have provided updated "IE Compatibility" test virtual machines, which now include an IE6, IE7 and IE8 Beta 1 virtual machine for testing your applications. Download available here: http://www.microsoft.com/downloads/details.aspx?FamilyID=21eabb90-958f-4b64-b5f1-73d0a413c8ef&DisplayLang=en
Microsoft also has a Run IT on a Virtual Hard Disk program. Using the power of virtualization, you can now quickly evaluate Microsoft and partner solutions through a series of pre-configured Virtual Hard Disks (VHDs). You can download the VHDs and evaluate them for free in your own environment without the need for dedicated servers or complex installations. Start now by selecting a lab from the VHD catalog below.