After looking I did come accross this post on the facebook forums:
They are feeding the facebook object a UIImage. That seems logical, but where is this documented? The API documentation is generalized to all platforms. Where are the iPhone specific requirements for arguments and their data types?
Thanks
******Update***** I still have not came across any API docs pertaining to Cocoa. I did, however, gather the information I needed by piecing together forum information, Facebook sample code, and some glue.
Hopefully they'll issue something a little more concrete over the next few months.
Graph Api documentation of Photo upload are follows..
https://developers.facebook.com/blog/post/498/
https://developers.facebook.com/docs/reference/api/photo/
And you can see how to do this in iPhone here.
http://www.raywenderlich.com/1626/how-to-post-to-a-users-wall-upload-photos-and-add-a-like-button-from-your-iphone-app
Joe Hewitt (the author of the Facebook iPhone app) released large parts of the Facebook application as his Three20 framework. It is hosted on github.
For completeness:
The following explains how to interact with Facebook Connect: https://developers.facebook.com/docs/guides/web/
The API calls: https://developers.facebook.com/docs/reference/api/
If you need extended Permissions: https://developers.facebook.com/docs/guides/policy/examples_and_explanations/Extended_Permissions/
A nice Obj-C wrapper on Mobile Orchard: http://www.mobileorchard.com/marketing-in-code-part-2-setting-a-users-status-in-facebook-from-an-iphone-app-a-tutorial/
What follows is my implementation of a SessionViewController: