2007 Microsoft Office System Virtual Labs
Well worth checking out!
The 2007 Microsoft Office System delivers an entirely new level of programmability and extensibility to Office client applications and new scenarios via Microsoft Office SharePoint Server 2007. It's simple — no complex setup or installation is required to try out 2007 Microsoft Office System running in the full-featured MSDN Virtual Lab.
http://msdn.microsoft.com/virtuallabs/office/default.aspx
