http://en.wikipedia.org/wiki/DC_conn...indrical_types

I'm referring to the end with two pins on it, that normally plug into
a small socket on the end of the cable that comes from the wall wart.
You can fit it two ways round to change the polarity. I've had a few
adapters, some with straight plugs and some right angled and they all
seem to fit, which seems to imply there's a standard of some kind, but
the article only refers to the end that goes into the appliance.

The pins are a tad over 1 mm thick, a little over 4mm apart point to
point, and 6mm long

Is there a name for this connector and does anybody know where you can
get them, specifically the female bit? I want to rig an external
battery pack that'll fit my camera, mp3 player, phone and anything
else that I [still] have the right end for.