you could use an external firewire HD box but you would be limiting the drives peformance to the firewire speed of 400, usb2 would be a little faster but not a lot in it to be honest. if its just storage and not required for speed then i would opt for a USB2 external hardrive unit. they come in many sizes one will surely suit your buget.
of course your PC needs to have USB2 or firewire to use either choice.
