[w3c] Accessibility of Excel docs?

Hello All:

Thanks for the information on the tables, everyone was most helpful! 

Now, I'm wondering about Excel spreadsheets.  I've been told that downloadable reader exists for Excel, but I cannot find it.  Does one exist?  Is it accessible? Other than an HTML equivalent, is there another method of making these documents accessible?

Thanks.
Brooke Dine
Information Specialist
National Center for Biotechnology Information (NCBI)
National Library of Medicine/NIH
Bethesda, MD 20892