In the back of the the 2011 NEC is a small paper flag with a limited time offer for a free PDF version of the 2011 NEC. You enter a code on the paper flag and then take an online survey, it took me three minutes.
You are directed to a log in page at the NFPA and then can download the PDF and a special software program to install the PDF version.
Keep in mind the electronic version of the NEC will not be available.
I asked Mark Early (NPFA Chief Electrical Engineer) about the free version, and he stated its not in all the 2011 NEC,s I checked several today and it was.