I'm trying to build a desk toy that has three small LED bulbs that come on automatically when the object is turned 90 degrees. Assumming that a small mercury switch between the bulbs and the battery would do the trick.... but I have no clue on following items. How do I determine what size bulbs to get and approx how many hours of life the battery would provide with a certain size bulb? (looking for something that would run a minimum of 10-20 hours) Is there another option besides a mercury switch (something a little more "shock resistant" would be nice) Where would I look to purchase these items (bulbs, switch) Pardon my ignorance, I am more of a woodworker than an electonics wiz. I appreciate any help I can get..