Which Sandy Bridge motherboard and CPU support overclocking?

The question of which Sandy Bridge parts support overclocking keeps popping up on forums so I thought it best to write out a post explaining this subject.

 Sandy Bridge CPU overclocking

Intel has changed the game when it comes to overclocking on its new socket 1155 sandy bridge platform. With older platforms you could overclock any CPU as long as the motherboard supported it. Now you need both motherboard and CPU support to be able to overclock the CPU:
K series CPU: To be able to overclock the CPU you will need a K series CPU. A K series chip has an unlocked multiplier that allows you to overclock it. You can’t overclock a non-k series chip.

K series chips are identified by the K prefix attached to the model name. At the time of writing only two K series CPUs are available. They are the core i5 2500k and the core i7 2600k.
P67 or Z68 chipset motherboard: You will need a P67 or the yet to be released Z68 chipset motherboard. These motherboards allow you to change the CPU multiplier so that you can overclock.

GPU overclocking

The interesting thing about Sandy Bridge CPUs is that Intel moved the integrated graphics from the motherboard to the CPU. So you can overclock the Graphics Processing Unit (GPU) built into any Sandy bridge chip. Even non-k series chip’s GPUs can be overclocked. But to be able to do that you will need an H67/H61, B65 or Z68 chipset based motherboard.
What if you want to overclock the CPU and the GPU? To be able to do both you will need a motherboard with the Z68 chipset which hasn’t been released yet.