The more I think about this, the sillier your assertion seems that having your application running in the background is a necessity for functionality like push-intents. Its like you are saying that without all your apps running code running all the time, Windows or the Mac won't know what app to use when you double click on a file. And if you want an example of how to offer a range of network services without having to keep all of them running all the time, try reading about inetd. Its a pretty new idea, but I'm sure you can find something about it.
An iPhone application has no way of having a long living listener for something that would resemble a push intent. The only thing you can do is register small bits of code as video/voip/audio services that can run in the background. Anything more advanced than that is reserved for Android or true multitasking OSes.