Hi,
I know this is really geeky but when I prototype with breadboards I always need double row headers for IDC cables (AVR pinout, PIC dev boards. LCD's etc..) I tried looking for the long pin headers, but gave up. So, 3 minutes with standard single row headers and stripboard...I built these.
You only need to cut between the rows of pins, I did it with a craft knife. The cool thing about this is you can make a 2x20 double row header, then cut it up into smaller ways, that way you only really need to make a couple of these.
Blueteeth.