How To Use the Three20 Photo Viewer

1. Install Three20 viewer:
git clone git://github.com/facebook/three20.git

2. Configure thre20 for your project
python three20/src/scripts/ttmodule.py -p PhotoViewer/PhotoViewer.xcodeproj Three20

refer more at: http://three20.info/article/2010-10-06-Adding-Three20-To-Your-Project

3. Write sample:
http://www.raywenderlich.com/1430/how-to-use-the-three20-photo-viewer

Note: if you can not configure the sample code in this link. Please create new project, configure follow step 1, 2 then copy code. I did like that, work like a charm.

How to load image from camera roll:
Can not load directly, must use UIImagePickerController to pick then save it to document
Then use url: documents://paht to file to load into Photo object