In iOS 6, clicking the action button in the Photos app is a standard UIActivityViewController:

The execution of the same message is a different set of parameters. I like it using the UIDocumentInteractionController api to pull out all the applications that say they can process the image.

My question is twofold:
How to get into the "Messages" action menu? Tumblr and Halftone, to name a few, did this ... I can not find the documentation.
? UIActivityViewController, ... //// ..
!