So is that a brand-new Dell XPS machine? Is that my aging-not-too-well Compaq Presario 1210 with a Pentium? Is that a Macbook Air? Is that one of Oracle's $200,000 M-series servers? Is that some beige-box piece of junk that the researchers found in their neighbor's backyard? The category "personal computers which do not exploit quantum-mechanical principles of computation" is so mind-bogglingly vast that such a description alone is hardly useful.