Dual Core 168 Arduino

"Siamese" sums it up quite nicely, Siameseduino is a bit of a mouthful though ;D

I'd say the boys here will be knocking out a 128 Arduino in the not too distant future, so this design will be irrelevant as far as we're concerned if it's not too expensive. But if it inspires creativity in the meantime, then that's not a bad thing.