Thermochromic dyes: Smart textiles: Heat Reactive Jacket by Stone Island, a tracksuit top which changes colour from black to green/ blue once it has reached 27 degrees. The fabric that is cotton nylon with thermosentive liquid crystals that react to heat.
Tokay Gecko - they are beautiful, they change colors, they can jump and climb your walls and hide on your ceiling, they have razor sharp teeth and will bite a huge chunk out of your arm if you get near it. They chirp like birds when mating and growl like the girl from the movie "The Ring" when angry. Very difficult reptile to have as a pet but worth it if you like lizards. Make sure you get two so they chirp at each other. NOT FOR CHILDREN! RIP my little buddy =(
Here's a diagram showing how to make a lizard out of pony beads. FYI-don't use Sgetti string as it isn't very flexible and doesn't allow the beads to dangle or lay flat. Use lanyard as yarn isn't very sturdy if kids want to hang this as a keychain. p_chemil.gif (8752 bytes)