Every time you want to leave your computer, you have to choose between nine, count them, nine options: two icons and seven menu items. The two icons, I think, are shortcuts to menu items. I'm guessing the lock icon does the same thing as the lock menu item, but I'm not sure which menu item the on/off icon corresponds to.
On many laptops, there are also four FN+Key combinations to power off, hibernate, sleep, etc. That brings us up to 13 choices, and, oh, yeah, there's an on-off button, 14, and you can close the lid, 15. A total of fifteen different ways to shut down a laptop that you're expected to choose from.
Source: Joel on Software