I'm just returning from a 3-day family & friend trip to Yosemite and there were 10 of us taking pictures with our cell phones. 3 were teenagers posting pictures to social media, mostly Instagram, and sharing some on our WhatsApp group. I mentioned the possibility of having a contest for best picture in different categories and the kids and some adults were excited to take part. The idea was to encourage photography and share the best photos and perhaps a few short videos. With 10 cell phones, there could be a thousand pictures, but I'd like the only better photos to be shared, with some indexing. Any suggestions would be appreciated.