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 pub

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/titles/amiphd/iphone-sdk-development http://www.pragprog.com/screencasts/v-bdiphone/writing-your-first-iphone-application http://www.pragprog.com/screencasts/v-bdiphone/writing-your-...