The ALDHA has made the PDF version of the 2010 Companion available on their web site.
http://www.aldha.org/comp_pdf.htm
It works fine in my Sony E-reader. It's still a good idea to support the ALDHA and the ATC by purchasing a hardcopy.
I'm carrying the E-reader instead of hard copy because I've got a couple of hundred books in my pack, it weighs less than a Pound, and it runs for up to 2 weeks on a charge.