Here at Intergen I have the good fortune of working with lots of very tallented people. 

 

One of them, James Newton-King, has developed a means of viewing Microsoft Word 2007 documents in a web browser, on any platform!

 

His solution, called TextGlow capitalises on the OOXML format used for docx files and is built using Silverlight 2.0. For more info read James' post: http://james.newtonking.com/archive/2008/03/06/silverlight-2-0-ooxml-textglow.aspx