A new milestone in the development of the iPhone OS 3.0 has been reached with the release of the 4th beta of the iPhone 3.0 operating system, just a few weeks after the release of iPhone OS Beta 3 (details here). According to reports on the web, developers have already been handed iPhone OS 3.0 Beta 4 SDK alongside a preliminary build of iTunes 8.2 (a pre-beta version of the iTunes software that is required for the installation of the iPhone OS 3.0). The build string attached to the iPhone OS 3.0 Beta 4 is “build 7a300g”.

The thing to keep in mind is that there is good reason why the software has been made available for developers only – because it is meant for testing purposes. It is still a work in progress, and no matter how excited you are about the new features included in the iPhone OS 3.0, you are better off waiting for the final, stable release (especially if you are not the “put everything to the test” kind of person that doesn’t handle bugs and problems very well). Think twice before using the iPhone OS Beta 4 if you manage to get your hands on it (picture a bricked iPhone for example). And no matter what, do not purchase this software from eBay!

Getting back to the iPhone OS 3.0 Beta 4, here are the changes that we are aware of:
- Installing iPhone OS 3.0 Beta 4 via iTunes 8.2 works fine. Installing the OS by using Xcode can result in a Pink Screen of Death.
- You are given options upon taking a picture. The software asks you if you want to save the picture or discard it and take another.
- iTunes 8.2 displays a timer for restoring backups.
- iTunes 8.2 syncs voice memos.
- Support for additional over-the-air PIM synchronization sources. This includes Google and Yahoo!
- Copy and paste in Calculator.
- Continued tethering support.
- The Store tab now presents user info.
- You can sync notes, but this requires Mac OS X 10.5.7.
- USB tethering enabled by iTunes 8.2 for Windows.