Linked by Thom Holwerda on Mon 18th Dec 2006 22:27 UTC
"If you pay close attention, you'll notice that most user interface actions tend to occur on the release, not on the press. When you click on a button, the action occurs when the mouse button is released. When you press the Windows key, the Start menu pops up when you release it. When you tap the Alt key, the menu becomes active when you release it (there are exceptions to this general principle, of course, typing being the most notable one). Why do most actions wait for the release?"