So let's look at the online office solutions:
Google Docs - http://docs.google.com
Zoho - http://www.zoho.com
I've been using Google Docs happily, then I got a Microsoft Excel 2007 price list from a supplier that is 2.5Mb in size. Google just will not load it because it is over the 1Mb size limit. Zoho tries, but then gives an error, no explanation, just an error. So now I had to look for a solution. I then tried opening the document on a Microsoft Office 2007 machine, removed all the fluf and saved it, still no luck. I even did the ZIP rename and removed the images from the file.
So of to Google we go, and there someone mentioned http://www.acrobat.com.
I registered for the free option (look for it in the signup screen), uploaded the original XLSX file as I got it from the supplier, and done. Very nice interface (Google Chrome) and the file is in a PDF format. Yes, some of the formatting isn't 100%, but I can view the file! You can then even share and download the file.
Give it a try.