Well only a weeks after the first iPhone 2.1 beta seed, Apple has pushed out another 2.1 firmware update for developers. Apparently, according to MacRumors, Apple has seeded the new iPhone 2.1 OS SDK beta to select iPhone developers with tools that are needed to create iPhone apps that take advantage of push background notification service.

We know Apple has made sure their core apps, Mail, iPod, Phone, text Messages, Safari, on the iPhone and iPhone 3G can run in the background, we know they have barred 3rd-party apps from draining the iPhones resources.

So to that end, Apple unvield the push background notification service at the iPhone 3G keynote. As you probably know, push background service lets 3rd-party apps receive updates via 3rd-party servers without the need to keep the app running.

Information from the 3rd-party servers would then be pushed to Apple’s push background services server then pushed onto the iPhone via a persistent background connection.

The push notification server allows for data that can be used to update pop-up text alerts, sound off notification, and update icons and such. And information can be pushed to all sorts of apps such as social networking and instant messaging apps.