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.