I've recently created a plug-in to allow the device screen (or a portion of it) to be saved to a file or the Saved Photos album. It's IOS only at the moment, I'm afraid (because that's my current focus) but will hopefully be of some use to others. It might also be helpful as further guidance to show how one can create a Gideros plug-in using Objective-C.http://www.bowerhaus.eu/blog/files/gideros_snapshot.html
The obvious use of this code is to save user creations to the photo library but there might be other uses such as a simple form of "render to texture" while we're waiting for that to make it in the Gideros API.
As usual the code is MIT licensed so use it in your private or commercial projects as you like.