Scientists found that heat moves through graphite in 'waves' at the speed of sound. What's weird about this is that heat generally bounces off of vibrating molecules in multiple different directions and doesn't usually move as a wave.
If heat can travel as a wave, it can move in one direction en masse away from its source, sort of zapping energy all at once from an object. Someday, this heat-transfer behavior in graphite could be used to cool down microelectronics in a snap. That is, if they can get it to work a reasonable temperature (they were working in bone-chilling temperatures of minus 240 degrees Fahrenheit, or minus 151 degrees Celsius).
Pretty cool, if you ask me! The research has been elaborated here!
Image Credits: Wikimedia Commons
In the superfluid helium, you basically end up with two components: one that acts like a normal fluid, and another part that has no viscosity and can essentially pass through itself. Boiling and normal convection stop when you get cold enough to go into that state, as the part without viscosity can carry heat from hot to cold very quickly and pass right through the other component.
Second sound comes somehow from the mixture of those two components, so a wave that changes the composition of the two also changes temperature, and you get a temperature wave. But it has been a long time since I took that class and I don't remember much of the details...