Apple has released the fourth beta of iPhone OS 4.0. This new beta includes many changes and additions, some known, and some not known yet. Here’s a list of changes/additions:

• More wallpapers added for the homescreen
• Tethering
• Default Utilities folder
• The GPS button in Maps now uses the same icon that will be used to indicate apps that use location in the status bar
• There is an option to toggle off the ability to send group messages in the Settings app

Currently, those are the only known changes/additions. Ultimately, the biggest change/addition in this new beta is Tethering for sure. Previous rumors have stated that AT&T will bring Tethering to the iPhone, however, the rumors didn’t state when it was coming exactly though. So, I guess this June when Apple will announce the next generation iPhone and release iPhone OS 4,0, you will be able to Tether your iPhone to your laptop or computer. Some of you may not know what “Tethering” is. Well, Tethering allows you to use your iPhone’s 3G or Edge connection for Internet access on your laptop or computer. iPhone OS 4.0 is expected to be announced next month at the WWDC along side with the new iPhone and iPod Touch. So, if you are a developer, go ahead and download this new beta!