Remember the Turbo button? Ten years ago it was all the rage, sitting on the front of your PC dangerously close to the reset switch. Ostensibly there to switch between the original 4.77MHz PC clock speed -- for compatibility with old software -- and the breathtaking 12, 33 or even 66 megahertz of your 486DX, it was really just an excuse for PC makers to include some extra twinkling lights for the speed display. These days both button and display are long gone: with PCs running more than five hundred times faster than the original, the cost of the display alone would probably wipe out the profit margin on the entire computer. You know how it is. With this thundering increase in PC power has come decadent ennui about the whole business. What's the difference between two or three billion calculations a second when you're waiting for some distant Web site to come lurching through your modem? Things get more interesting when you consider the flip side of great speed: great precision. A clock speed of two gigahertz means that the processor slices each second of existence into two billion parts, a temporal microscope into events that would be unimaginable just twenty years ago. This gives computers an incredible facility for working with time, one that's so novel that it's easy to overlook. But the Web is beginning to show that people are waking up to the possibilities. I've spent the past couple of evenings listening to Beethoven's 9th. Well, part of Beethoven's 9th -- the original goes on for an hour or so, but this version, 9 Beet Stretch, has been pulled out to 24 hours by an ingenious Scandinavian called Leif Inge. The clever bit is the software that keeps the pitch of the sound the same while expanding the scale of the music; the result is far more beautiful than one would suspect. Elsewhere on the Net, you can grab boots -- two or more pop music tracks sped up, slowed down and mixed together in bizarre and occasionally hilarious ways -- or any number of variations on famous works. Even Windows gets in on the act: the tiny burst of music written by avuncular agent of the avant-garde Brian Eno to start up Windows 95 plays at double its original speed, due to Microsoft's concern not to bore the punters. This is the beginning of a brand new wave of creativity, and we can all play. Art is about time: a picture or sculpture stops time indefinitely, while a novel or a film speeds it up, compressing the events of days, years or millennia into a single experience. This is rarely explicit -- cutting forward in the narrative is so much part of the experience we almost never notice it. Even when the cut disposes of all human history in one 24th of a second, as when Kubrick's orbiting space station displaces the apeman's bone in 2001, we accept it in a blink. Manipulating time in other ways is rarely done, because it's so much more difficult. Until now.