M IT was so advanced in 1965 (the year I entered as a freshman) that it actually had a computer. Housed in its own building, it cost $11 million (in today's dollars) and was shared by all students and faculty. Four decades later, the computer in your cellphone is a million times smaller, a million times less expensive and a thousand times more powerful. That's a billion-fold increase in the amount of computation you can buy per dollar.