Ramblings from another nerd on the grid
Office Web Apps gives users a browser-based viewing and editing experience by providing a representation of an Office document in the browser. When a user clicks on a document stored in a SharePoint document library, the document opens directly in the browser. The document appears in the browser similar to how it appears in the Office client application. The Web app also provides many of the same editing features as an Office client application.
Go get it @ http://www.microsoft.com/downloads/en/details.aspx?FamilyID=515dd67e-3ff6-4f0d-bc45-cfc8ba742055.