Mate of mines gone and bought himself a bigger 2.5" drive for his macbook thing, but the ones hes got is larger than a standard 2.5" drive, its 1.3cm deep as opposed to the normal sub 1cm..
So he wants an external usb/firewire caddy for it, he likes the look of the Akasa P series but they dont say how big physically a drive they can take.
I would of thought something with a fan if possible but will leave it to your guys suggestions...