Few Days Ago i received my Apple Keyboard and i am enjoying typing on it, but having to hold down the Fn key then tap one of the F-keys to get F-keys working was irritating.
a simple solution to get it working just add this to your /etc/rc.local file
echo 2 > /sys/module/hid_apple/parameters/fnmode
and F-keys will start to work properly, enjoy
Update :- update for recent kernels,