Business Insider heard a rumor that Apple's iPhone 3.0 operating system may have support for applications that run in the background:
Apple might allow users to select two apps that can run in the background. Specifically, one source says there's some evidence of this in a new beta of Apple's iPhone 3.0 software developers kit. (We don't have the SDK, and wouldn't know where to look if we did.)
Apple might selectively allow some apps to run in the background. We assume that developers could apply for permission to run in the background, and that Apple might approve or deny them based on the resources they need, how well they behave with the operating system's stability, and how much network bandwidth they need.