I think if you can program and wire something in 8-bit, it can be done in Minecraft. Or something. I'm sure someone made a computer that could hold 8 bits of memory. It took up several game chunks to build.
Very cool. However, I stopped messing with Minecraft b/c I don't like to play games online with people, (I don't do XBOX Live, PSN, or anything, just not into it.) and there's really no point to the game, aside from setting personal goals. So I just stopped.