Hidden Leopard feature: System Profiler
Here’s a neat Leopard trick I haven’t seen anywhere else.
Hold down the option key while choosing > About This Mac, and the menu item will change to “System Profiler.”

That’s much quicker than the old method of (i) select About This Mac, (ii) click “More Info” (iii) close the about window.
January 9th, 2008 at 9:12 am
Pressing option while the File and Window menus are visible also reveals some little extras.