Quick note: I came across this last night and don't know if it's shown up anywhere else, but I think it's one of those great examples of how life imitates fiction.
Ever read The Diamond Age, by Neal Stephenson?
Well here it is, coming to life. They're taking Charles Babbage's Difference Engine and nano-izing it: making chips (probably out of diamond, no less) that are based on mechanical principles rather than electrical ones.
Hooray for fiction writers!