In creating an iPhone app, is it possible to generate a popup alert on the iphone (similar to a Push notification) when the app has been closed. A simple example would be t
Unfortunately, no. This would require some sort of background processing for your app, and that is not allowed in the current iPhone SDK. Push notifications are the only solution I'm afraid.
If it's an issue of development effort, I know Urban Airship has some solutions to make Push Notifications easier.