There are two versions of Navigo: The regular one, which is what you have, and the Navigo Découverte which has been recently introduced. The Navigo Découverte costs 5 euros for the pass, which is issued on the spot and is valid for 10 years. Both versions require an ID photo. The main difference between the two is that the Navigo Découverte is not registered to its owner and thus can't be replaced if lost.
Great info! Do you know where one can get a Navigo Decouverte?