The folks down at FanlessTech found a giant heatsink that Antec showed off at Computex. It consists of three large stacks of aluminum, weighing about 3lbs, with potentially four fans moving air slowly across it. The original post doesn't mention whether it could be used in a fanless mode, but come on. It should be able to cool something without a fan directly attached to it.

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They don't seem to have price, availability, or even a model number yet, so details are scarce. It will have at least three colors, black, gold, and red, though, so you have a choice about how it will look in your case. Well, at least mostly in your case.

Update (June 5th @ 2:20pm): Turns out that I forgot to add the dimensions and specifications of this cooler. Its total size is 165mm x 142mm x 159mm. Its intended fans spin at 800-1800 RPM. At 800 RPM, they push 12.36 cubic feet per minute of air at 17.5 dBA. At 1800 RPM, they push 65.23 cubic feet per minute of air 25.9 dBA.