Ferrofluid is a really interesting material. As the name suggests it is a runny fluid....until it is subjected to a magnet. Ferrofluid reacts to magnetic fields, often changing into seemingly impossible shapes as it tries to maintain the shape of the magnetic field. More information about the Ferrofluid - Magnetic fluid

Polymorph is a fascinating new type of material. It is perfect for hobbyists whether you are model making or prototyping. At room temperature it just as strong as a normal plastic but at 62 degrees C becomes soft and mouldable. More information about the Polymorph - Low temperature melting plastic