I'm currently saving up for another camera since, when shooting events for motorsports and charity work I tend to switch back and forth between two lenses a lot and it's a major pain. -Having two cameras means I'd have both lenses mounted and ready to go at all times. There are also a couple annoyances with my current camera that would be fixed with a new one (size and layout). Cash would be much appreciated as it'd help me get my new camera sooner .
Other ideas:
Books: