""Brainwave - Make the computers out of carbon thus making your computer carbon neutral.""
"That day might yet come - the carbon transistor already exists: http://www.theregister.co.uk/2008/01/29/carbon_nanotube_radio/"
"Hmmm... and to think back in 1981, I suggested to my chemistry teacher that since germanium and silicon were used as semiconductions, maybe carbon could be too, and he didn't take me seriously"
Carbon is definitely a semiconductor. Even back when incandescent light bulbs were made with Carbon thread filaments, it exhibited semiconducting effects (The resistance decreased with increasing temperature.). Of course, for it to really be useful, it needs to be in a certain form (e.g., nanotube, or crystalline). Thus, we have diamond transistors:
I can see the future now. Us geeks won't be asking each other how many gigabytes of memory our systems have, or what the processor speed is; we'll be asking each other how many carats our systems have in them. ;-)
P.S. Think that'll get more women interested in IT? Err, I'll get my coat...