So it’s Leopard Day. The official release is at 18:00 EDT, but mail order copies of Leopard have started arriving on desks around the world. There will be a sharp drop in productivity today as Mac fans upgrade their operating systems. If you are ready to upgrade, you might think about going for a clean install, it will be almost like getting a new Mac.

If you’re not quite ready to upgrade, check out, The Unofficial Apple Weblog’s 24 hours of Leopard, TUAW’s favorite new Leopard features–in 24 parts. If those shiny, new features don’t encourage you to loiter at the Apple Store tonight, I don’t know what will.

Photo by Obi Juan Kenobi