Apple thin keyboard

just bought an apple thin keyboard to replace my old one, but wondering what the F13 to F19 buttons are for?

Now the volume buttons are over F11 and F12 whereas they used to be over F16 and F17, and it looks like them 2 keys now havent got much of a purpose?

Nothing within the OS as of yet. But some apps might use the keys.

Or this link might be of use if you want to make use of those redundant keys.

http://www.macosxhints.com/article.php?story=20050801052917667