So when I was checking out GBM-GC cables on ebay (yep, Troz1820 is still the only answer), I found this GBM-USB cable:
http://cgi.ebay.com/USB-2-0-Cable-for-Gameboy-Micro-GBM_W0QQitemZ8291904002QQcategoryZ122515QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
"Update your GBM at high speed with the...