Japanese researchers have developed "melody roads" that play tunes when you drive on them. You could use this technique for traffic calming...i.e. the road plays music only when you're driving the speed limit and hope that there's no second-order melody that plays at two times the speed limit to entice highway hackers to speed for forbidden tunes.
...is a weblog about the liberal arts 2.0 edited by Jason Kottke since March 1998 (archives). You can read about me and kottke.org here. If you've got questions, concerns, or interesting links, send them along.