Last night I pre-ordered my copy of Programming Erlang: Software for a concurrent world.
After having read the example chapters I think this is going to be a really good book on the subject. Granted, by the time it gets here I may not really need it, but it will still be nice to have.
One of my favorite things about buying books like this is that I can get a better view of what the author thinks is really important about the language. Instead of a language reference where everything is given equal time. (because that's what you need in a reference) You get a view of some of the best practices around using certain parts of the language.
Languages have syntax, libraries, and idioms. You don't get the idioms from the library reference. You also don't get them from the language reference, it's too busy describing the syntax.
I like what I've seen, and I'm excited to get my copy when it ships later this summer.