You mean on the Macbooks?
It's an Express Card slot for putting Express Card 34/54 in.
You can get Express Cards that do all sorts of things - memory card readers, Wireless Receivers, eSata terminals.
You get the idea.
Panzer
Sorry mate, I wasn't trying to sound patronising, should have put a smilie in there to show you my reply was a bit tongue-in-cheek.
Panzer
