I've used CamelCamelCamel a few times - they let you choose a price, and they'll send you a notification when the price drops below that. Something that can det

I've used CamelCamelCamel a few times - they let you choose a price, and they'll send you a notification when the price drops below that. Something that can determine when the price is at its lowest based on previous trends would be pretty neat.