Admins: I was not sure where to post this, but this seemed to be the most obvious choice to me. Please move if you see a better choice.
Just caught news of an (apparently) new site that is without a doubt the most in depth guide to gun laws, listed state by state, and reciprocity I have yet seen.
GUNLAWSBYSTATE.COM is free to access at any time via the net, and is apparently going to be updated on a constant basis.
Question and answer type mini threads run alongside the laws as you read through, allowing you to both view or ask questions and either read responses by the author, other posters, or write your own as well.
You have the option to purchase a non-interactive hard copy of the book for offline use, and there is a Kindle version for purchase as well.