Config a function key to activate the [App : Show All] command [my first question here...]

Is there a good way to map a function key to do the [App : Show All] command? i.e. Un-hide all apps.

BTW, i currently use Spark to map function keys.
Check out the Keyboard preference pane:



In the Keyboard shortcuts tab, click the plus to add a new shortcut. Set the dropdown to "All Applications" and then type "Show All" (case sensitive!) as the menu item. Map it to whatever you like.