In Pictures: A sneak peek at Apple's upcoming OS X...
Apple has implemented iOS's share sheets technology in several Mountain Lion apps; developers can add them to their apps as well. A share sheet provides a quick way to share whatever you're working on -- a photo in iPhoto, a website in Safari, a document in Notes -- with other services. The key is developer access: Apple has given developers a standardized platform for sharing, which means that even as more apps start to make use of share sheets, the user experience will remain consistent.
In Pictures: A sneak peek at Apple's upcoming OS X Mountain Lion