Can't find where to send in suggestions, so I'll post here:
The Google Docs viewer NEEDS to have a rotate button. I receive faxes online and 90% of these come in upside down. Downloading just to rotate 180 degrees in Adobe Reader or another program is tedious and would be entirely unnecessary if a simple rotation was possible in Google Docs viewer. We've got a print button and a zoom in and out button, rotation would be a great addition.