Prowl: Growl client for the iPhone - Any notification over push
prowl.weks.net
prowl.weks.net
I wonder how it works out for the dev if users use it heavily for years paying only a one-time 3$...
a) A Growl-enabled computer running and connected to the Internet; or b) Your own server somewhere making API calls to create the push notifications.
It might work for iTunes Store developers to get cheap pushes to their customers, but other than server notifications (i.e "Server A is down, please ring so and so"), I'm not sure how useful this would be to the general public.