Money saving tips and more please!?

Alright so I really want the Nikon D3100 camera! My little digital one is crap, it's 8mega pixels and sucks! So my mother and I made a deal that if I save up all the money necessary for it, (around $700Canadian because I live in canada). So far I have $70, my plan was to buy the camera on boxing day when everythings on sale, this summer i'll be babysitting but I highly doubt I'll make enough for the camera. So I need ideas for how to make money and how to save money! Please!