Part of the innovation in replacing the default gallery application in Android is having meta-data used of generating tags that than are assign to user defined categories, sort of an automated organizer of sorts. Obviously, I can use file names as the first version of this feature.
But, with all the buzz in getting higher GHZ devices into th market not just the low end at 800 MHZ at the low end but the ones at both 1 GHZ and 1.5 GHZ cpu speeds it would seem that innovation of tagging should use image processing. For people objects that would be called face recognition, for non people object its called object recognition.
You the user choose an image on the SDcard and Gallerie calibrates the tagging of that object in the picture so your photo album has all the pictures on the Sdcard of that object in one album. with the new device cpu speeds it should be fast enough as I would be using an Android specific processing.org image library. I could even make this the premium feature and the picture tagging by file name the freemium feature.