Hey, I am an Android developer and I have experience with photo/video selection from gallery and storing that data (I had developed an app that lets the user select photos/videos to sent as mms in sms autoresponder application).
For loading selecting pictures I would use not the pictures themselves, but references to those pictures, so it won't cause any lags or OutOfMemoryErrors.
Of course I would like to hear further functionability of this application (what to do with selected pictures, ect.) to give you more information about how I would make this application.