Jan 13, 2011 08:21 GMT  ·  By

Apple has seeded the first internal builds of iOS 4.3 to developers, documenting quite a great deal of changes, from the added option to toggle the hardware switch between “mute” and “orientation lock,” new multi-touch capabilities on the iPad, the person hotspot feature mentioned yesterday, and more.

Apple's first iOS 4.3 beta is available for iPod touch (3rd and 4th generation), iPhone 4, iPhone 3GS, iPad, as well as for Apple TV.

One of the first noteworthy changes is actually the lack of support for older-generation devices - iPhone 3G, and second-gen iPod touches.

iOS 4 never worked well on these units anyway. Apple is now indirectly admitting it, by completely scrubbing them off the compatibility list for iOS 4.3.

As noted above, Apple is also throwing in an iOS 4.3 build for second-gen Apple TVs, developers are reporting.

Code savvy individuals are asked to test AirPlay functionality from their apps using this build.

As expected, the betas include the new Personal Hotspot functionality for GSM iPhones.

Additionally, Apple documents new features like 4 or 5 finger multi-touch gestures on iPad, an option to use the hardware switch as orientation lock or mute switch on the iPad (highly requested feature from the iPad userbase), AirPlay streaming from third party apps, and iAds for the iPad.

“iAd full screen banners grab the attention of users by taking advantage of the large screen of iPad to launch an immersive, interactive iAd experience.”

"This new banner format is easy to implement. And Apple sells and serves the ads to your app while you collect the 60% of the advertising revenue generated,” the company explains on its web site.

Recent findings indicate that a new feature called "Find My Friends" is also making its way into iOS 4.3.

The code strings are associated with the Settings app and is related to "MobileMe," MacRumors informs.

Apple is believed to plan the introduction of a location-based friend-finding service similar to Google’s Latitude solution.

Those enrolled with Apple's Developer Program can download the iOS 4.3 Beta from the company's website.