Yesterday, Apple previewed its iPhone OS 3.0 software and announced the immediate availability of a beta software release to registered developers, along with a beta of the new Software Development Kit (SDK).

According to Apple, the iPhone OS 3.0 beta release includes an updated Software Development Kit (SDK) with over 1,000 new Application Programming Interfaces (APIs). Those include In-App Purchases; Peer-to-Peer connections; an app interface for accessories; access to the iPod music library; a new Maps API and Push Notifications, among others.

In total, over 100 fresh features will be available to iPhone and iPod touch users this summer, including cut/copy/paste, MMS, landscape view for Mail, Text and Notes, stereo Bluetooth, syncing Notes to the Mac and PC, shake to shuffle, parental controls for TV shows, movies and apps from the App Store, and automatic login at Wi-Fi hot spots. The iPhone OS 3.0 beta release will also include a new Voice Memo app and expanded search capability for all key iPhone apps. Search will be available across all key apps by typing a key word or phrase into the fresh Spotlight search, conveniently accessed from the Home screen.

An updated Stock app will add the ability to display recent company news and current trading information like opening or average price, trading volume or Market Cap and more. The app will offer a landscape view to those who wish to see a full screen of any stock chart. Shared calendars will also be viewable right on the iPhone with CalDAV support. Users will be able to sync their calendars with iCal, Yahoo, Google and Oracle.

iPhone users will benefit from a free upgrade to the new software, while iPod touch owners will have to pay the usual $9.95 for the fresh features.

“The new iPhone OS 3.0 is a major software release packed with incredible new features and innovations for iPhone customers and developers alike. It will keep us years ahead of the competition,” said Philip Schiller, Apple’s senior vice president of Worldwide Product Marketing.

Check out this piece for more great stuff announced by Apple yesterday (especially for developers).