Wanting to try Vista but not ready to perform a full upgrade just yet? Vista has been added to a pretty large variety of products which can be downloaded as virtual machines for evaluation. The S3 Ultra 64 video card in virtual machine hardware will not show off the visual capabilities of Vista but this is still a good way to test application compatibility. From the site:
For organizations with complex desktop infrastructures, whether large or small, Windows Vista Enterprise is the operating system designed specifically to help realize a better return on IT investments. In this VHD, you'll have the opportunity to road-test new and improved features including management (e.g. MUI, BDD, etc…) usability (e.g. Search, Navigation, etc…) and security (UAC, Windows Defender, etc…), enhancements to the Windows Vista platform.
Download details: Windows Vista