How can I secure a door with a window right next to it?
There is a product called Window Security Film which is a thin (a couple mm) film that adheres to the window and makes it exceptionally difficult for someone to break. Many lock smiths/security companies can install it. Here's a video of it in action: http://www.youtube.com/watch?v=vYdVK3BqPfk

This is a duplicate of my answer from this question.