There is a Word 2007 viewer. It can be downloaded from here:
View, print and copy Word documents, even if you don't have Word installed. This download is a replacement for Word Viewer 2003 and all previous Word Viewer versions
(my bold)
However, I haven't installed it so I can't comment on the UI.
However, it also states:
The Word Viewer, together with the Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats, allows you open Word documents saved in the following formats:
My reading of this is that you need to install the compatibility pack as well to actually read .docx files.
doesn't works very well for my documents? Can you provide more info. – Shevek Jun 7 '10 at 10:48