I found a 2x3 6-pin connector. It's a "DUAL POLARIZATION QUICKIE III FEMALE CONNECTOR, 2X3 POSITION" made by Berg (who is a part of FCI).

Unfortunately, it requires a ribbon cable, which means
you'll have to strip and separate each individual wire
on one end. But from what Rob tells me, I guess that's what people are doing already.

It's available from Allied Electronics
(www.allied.avnet.com, stock no. 518-3150) for $0.66,
and includes a strain relief. So is the ribbon cable
(stock no. 942-0901), which is $0.41 for 1 foot of 9
conductor cable (just rip off the extra 3 wires).

It's not currently in stock, but I believe their lead time is 1-2 weeks. If you don't want to wait that long, chop up a box header like it says on Rob's page.

I can design a PCB now, so for those of you that would be interested (in just the PCB or all the parts), send me an email. If enough people are interested, I will get some boards made.

Josh