I love the idea of adding the handbooks to my iPhone, as it would be a great way to know which cartridges that I already own, when I am shopping. Also, once they were downloaded on my laptop, it was really easy to side load them onto my nook. This has been useful, as now I can plan my next project when I am waiting in line to pick up my son from kindergarten. It's so easy, since it is all right there together.
I also want to point everyone to FCCB design team member, Jilliene at Jilliene Designing. She has a blog post where she had linked almost all of the cartridges, just updated in September 2013. Using her post, I was able to download almost all of my handbooks really quickly.
I hope you find this a useful tip and spend some time getting organized.