I found some SD adapter plans on gamesfairy . The PCB layout is
drawn in Pad2Pad , but I couldn't get the software to run on Linux
using Wine. So, I drew up a PCB myself using Eagle , which does run
on Linux. I then found some instructions  to use a laser printer to
transfer the toner from a PCB layout printed on photo paper to a PCB.
This is my first time ever drawing a PCB layout, so I was wondering if
some kind soul might take a look at my layout  to see if it looks
happy, healthy, and well. The design uses two fly wires, which are
drawn as the bottom layer.
I haven't figured out how to export the PCB layout to a format
suitable for printing yet, but I'll get there...
 http://www.sfu.ca/~sdj/tmp/gcsd.png http://www.sfu.ca/~sdj/tmp/gcsd.brd