I think about an option similar to the one in sony ericsson cell phones (I think other manufacturers have similar option too ) to add a frame to pictures, on cell phones it looks something like
http://www.techtalkforfamilies.com/files/Dale/Little_Tikes_Camera02.JPG -but I think more about vignetting or old camera film with dust - we can use raw merge for this - first creating a raw file with the vignette on a pc - saving it to sd card and after shot merge it with the photo.
This should be preety simple because we only need an editor for creating the raw files for all supported cameras but we can extend it with an option to see the picture with the frame before shooting the photo - just like on cell phones or a possibility to create the frames on the fly in the camera so we can create timestamps on photos (maybe we do not need full resolution then but only the needed part of the picture)
