Apple on Tuesday afternoon provided its vast developer community with a second beta release of iPhone Software 3.0, which arrived alongside a promise by the company to gradually open its live Push Notification service and In-App Purchasing to beta testers in the near term.

The Cupertino-based iPhone maker reportedly told developers downloading the build, labeled iPhone OS beta 2 build 7A259, that they could begin developing applications that will rely on the company's new Push Notification service immediately.

Similarly, developers were also provided with more detailed information on how to build in-app purchasing functionality into their existing or future applications. Much of this technical information will reportedly appear in a App Store Kit reference guide.

Apple said it plans to open its live testing services that support these new services during the ongoing iPhone 3.0 beta test program, but warned that access would be limited to a chosen few developers at first, and gradually expanding to more developers as time progresses.

In an article published last Wednesday, AppleInsider reported that Apple engineers were "racing to deliver a new build of iPhone Software 3.0 to iPhone and iPod touch developers" that would support "live support for Push Notifications through Apple's servers."

Meanwhile, developers familiar with the new beta say Apple appears to have knocked out quite a few bugs that were reported by testers of the original beta released on March 17th. (A comprehensive walk-through of changes in this build is available here.)

Another series of changes were reportedly documented alongside the release of a new version of the iPhone SDK also released Tuesday. Some specific components that received attention were GameKit, Bluetooth, MapKit, Fonts, the messaging user interface, and text fields.

Apple has also reportedly confirmed that MMS messaging and device tethering won't be supported at all during the iPhone 3.0 beta test.

Changes in Beta 2

There's reportedly a new menu item in the system preferences labeled "Store" that contains no data.

The build runs much faster than beta 1 and includes substantial stability improvements.