I use the keyboard a ton, and I found myself almost twice a week having to look up the keys to drop the menu in a ComboBox control. The right stuff tends to be buried in large documents, and I wasted a lot of time digging through them. No more! Now I can just check my blog, and hopefully Google will index it and others can find it more quickly.
F4 works, and so does ALT + DOWN. I like F4 better, because it can’t accidentally activate the window’s menu.