Is this really the "official" book? Official usually means that it's endorsed by the company that makes the product but I've never heard of Apple giving any publication "official" status.

I grabbed these two products but haven't had the time to check them yet:

http://www.pragprog.com/titles/amiphd/iphone-sdk-development

http://www.pragprog.com/screencasts/v-bdiphone/writing-your-...