Where can I legally download SAO light novel in English? Are there any legal sites where I can download the complete English Sword Art Online light novel?

I can't seem to find translated ones.
A quick google search shows that Barnes and Noble and Amazon have the paperback novels for sale:

http://www.barnesandnoble.com/w/sword-art-online-1-reki-kawahara/1116946707
http://www.amazon.com/Sword-Art-Online-1-Aincrad/dp/0316371246

These are obviously not downloads, but you can request nook or wait for kindle versions to be released, which would be digital downloads.

These are not free as legal usually means you pay for it unless its so old that the licensing has expired.