With all due respect, adequate piracy checking code is widely (read: freely) available out on the interwebs. Here's a link to Jeff LaMarche's blog on the topic, where no fewer than three techniques are outlined:
iPhone Development: Anti-Piracy Snippet.
There may come a day when these methods are ineffective and a more aggressive technique is required. But for the time being I believe them to be more than adequate for detecting a pirated instance.
