Over at Shop.com, you can buy spoons that turn red when your food turns a certain temperature (120 F). This is a good idea and all, but they should have made different options available, like at which temperature the spoon turns red.
Another way to make these spoons more popular is to turn the effect around; The spoon would turn a certain colour when it cools down to a certain temperature. You can buy the existing spoon in a pack of 3, which will cost you $9.50 over at Shop.com.
Hypercolor Spoons: Red When Your "Soup" is Hot [Via: Gizmodo]