Is it possible to run a background process on the iPhone using private APIs?

Question

I am not planning to send the application to the store, it would be for a limited distribution. I was thinking that if I could use the private API to do background process,

Answer 1

Probably against the SDK rules, even for enterprise deployment.

But blocking in - (void)applicationWillTerminate:(UIApplication *)app will probably work.

(there's a clever solution here: How to implement Daemon process for background task in iphone sdk 3.0?)