I've used a separate point-and-shoot camera and a USB cable adapter to connect to the phone to send the (few) pictures that I wanted to share immediately. The camera was very compact and I have enough of an interest in photography that it was worth it for me, but of course, it is another gadget to carry.

Your battery capacity seems to me like it would be enough. I've done three days with 2000 mAh in the phone and 4400 mAh in an external battery, and it was plenty. Very little photo-taking with the phone, though, but GPS tracking running and some podcast listening at night.