An anonymous reader writes "It finally happened. Steve Jobs announced an iPhone SDK today. The plan is to release it in February, and the suggestion is that apps will need to be digitally signed (not unlike digital signing in Leopard). Here's hoping that developing for the iPhone/Touch will be cheap (or free) enough to allow the folks who have been writing apps to continue doing so. Says Jobs: 'It will take until February to release an SDK because we're trying to do two diametrically opposed things at once--provide an advanced and open platform to developers while at the same time protect iPhone users from viruses, malware, privacy attacks, etc. This is no easy task.'"