I just recently had an idea and it's probably something people have tried before, but I'll give it a shot anyway.

What if your metallic case could also act as the heatsink for your CPU (and maybe other things)? I've taken all the basic sciences and my understanding is that when it comes to a good heatsink, two things are key: conductivity and surface area. Obviously the more conductive to heat the substance is, the faster it can pull the heat from whatever component it is meant to pull heat from. And the more surface area the cooler has, the more heat that can be transferred to the air around it.

So, given those two facts, one could argue that a metallic case could act as a very good heatsink if made from the right materials. If you had your case entirely out of aluminum (not the best conductive metal, but close) and you could get enough heatpipes from your component to the inside of the case wall, then you'd be able to spread the heat around a vast surface area. Also really helps if your case has good airflow, because then you're moving heat away from a large surface area instead of a small one and more of the flowing air is put to use.

I know something with this kind of construction would be pretty difficult (even moreso to make it doable by the average PC builder), but it is an interesting concept, isn't it?

Edit - I imagine this would make for a very interesting case mod. And while it may not be very practical to the average PC builder, it could have applications in laptops since everything is bunched together so much. I mean, if you found a way to have laptops spread the heat around and manage it all better, then we'd all be able to avoid burning our laps with high-end 'portable' machines because instead of a small hotspot on the bottom that's roasting your groin, you've got a warm whole laptop that might feel comfy.

I'm no expert, but wouldn't an entirely conductive case have issues with static discharge and the frying of one's components?

The entire inside of most cases is already a conductive metal (at least my Antec 900 is) and so far I've had no problems with static discharge cause I always ground myself.

Your not the first, in fact they made one already.

http://www.tgdaily.com/content/view/37832/135/

Zalman has had one for a long time for consumer purchase:

http://www.frozencpu.com/products/ [...] l=g1c7s434

It is entirely heatpipe to external heatsink design.

Wow, learn something new everyday. That Thermalright case looks wicked sick.

there are no problems with static because the motherboard is attached to the case via "spacers" which stop it short circuiting....otherwise every time you touched your case you would be electrocuted, lol!