Hole into the top of a frame (*basic question*)

Hi guys,
I've popped over from the Engravers section of the forum for what I imagine is a pretty basic question...
I am after putting a slot into the top of a picture frame, similar to what you can see on this image: http://www.englishrosestationery.com...0/SAM_0098.jpg

Is the best best way just to use a router or is there a better way of doing it?

(.-.)

Hole into the top of a frame (*basic question*)