iPhone development time

If you have an OO language under your belt and have a mac, these are reasonable minimums for the creation of your first, simple application (based on my own experience):

• 2 weeks: Learn enough Obj-C and iPhone SDK to create a simple 2-3 screen app.
• 2 weeks: Create and polish a beta version of the app.
• 1 week: Do a beta test of the app including 1-2 experienced iPhone devs.
• 2 weeks: Submit the app to Apple and wait.
• 1 week: Administrivia: Setting up a developer account, bank account info, and going through app submission process for the first time.

So a total of 8 weeks, or two months, minimum, if you keep the app simple.

iPhone / Apple specific pitfalls that will delay you (i.e. other than things that would delay any app developer, such as feature creep):

• Registering as a corporation (more complicated than registering as an individual)
• Failing to read the Human Interface Guidelines
• Failing to get at least one other iPhone developer with titles on the store to test your app
• Let me add to that, including content which "ridicules a public figure"

Learning resources that I found helpful:

• Beginning iPhone 3 Development: Exploring the iPhone SDK (PDF version)
• Stanford iPhone course video lecture series

My first app took longer than this, about three months start to finish. I was a little more delayed because I registered as a corporation, spent about a week making small, unrelated "test" apps, and ran a longer beta test. My app had a total of 7 screens, 3 of which required some moderately complex UI logic. In addition it required writing scripts to convert a large data set w/ images, and copy editing a lot of bilingual text. You can check out a video of my first app that took about three months to create from the time I started learning Objective-C to it's first day of sales on the App store. If your app is less complex than this, then it will almost certainly take you less time to launch it.