Camera (opt)
This is the one piece of equipment that the Guides will let you bring irrespective of size and weight! If you are a keen photographer by all means bring a large camera, though bear in mind you will spend a lot of time carrying it and saving weight in your backpack is paramount.
A compact model probably makes more sense, or even better swap emails with the other climbers on your course and share their pictures (you will also probably end up with more of yourself this way).