Please note that as of Dec 2014, this NO LONGER WORKS due to a security setting change on Pinterest. I’ll leave it here in case the creators of Download Your Board figures out a way to get around that. Until then, I don’t know of a reliable option for downloading entire Pinterest boards. Sorry.
This is useful for Pinterest users and non-users alike, basically anyone who might care to grab a collection of pictures that have been gathered on a Pinterest board, in one quick swoop. How and why you use it, whether to backup, steal, borrow, translate to another format like presentation, etc. is up to you. It’s just an awesome tool providing a magnificent service.