IDEA #2 – An educational constellation globe. As the user touches a star, the constellation it belongs to would light up. It could possibly be made using a light sensor behind each star, but that might get too complex..
IDEA #3 – RGB Lamp. This lamp would have three (or six, or nine…) simple LEDs in it, one of each color, and a light diffusor. Each color would have individual adjustments so that the user could play with the colors, either by making the lamp colorful, or by adjusting the color temperature to a warmer or cooler white.