Nitinol is a metal alloy, and its name stems from its roots: This blend of nickel and titanium was developed at America's Naval Ordnance Laboratory in the 1950s. The stuff is capable of exhibiting a surprising level of shape memory when exposed to a temperature differential. Check it out:
Product design applications, anyone? I've got a pretty brilliant one: Make headphone cables out of it. That way, if you're in Alaska and they get tangled, all you've got to do is fly to Brazil and they'll magically unkink themselves!