I see your gallery has location tagging support. I'm not sure how you are doing it right now (though I assume by hand) but I was thinking you could put your GPS shield to use as a geotagger. Either hit a button on it each time you take a picture to log the location and then match it up with your file name or you could constantly log the location and time and use the timestamps of the photos to pull out the appropriate coordinates. The latter is less hassle while shooting, but requires more Arduino memory and likely fancy software to cross reference your logs and your photos, but something I've thought would be neat to have (if I shot more photos, that is).