I have got my Apricorn housing back and the WD 100gig SATA notebook harddrive in it is also jumpered RPS.
Please ignore my earlier dull comments about SATA drives and Master, Slave and Cable Select jumpering I was obviously having a "senior moment"
Here are some links to typical USB adapters:
http://www.geeks.com/details.asp?invtid=2020&cat=HDD
http://www.geeks.com/details.asp?inv...504-DT&cpc=SCH
http://www.cyberguys.com/templates/S...roductID=12596
http://www.cyberguys.com/templates/S...roductID=13779
http://www.newegg.com/Product/Produc...82E16812200155
http://www.newegg.com/Product/Produc...82E16812186036
Typical IDE and SATA harddrive jumpering:
http://wdc.custhelp.com/cgi-bin/wdc....cF9jdj0mcF9zZW
http://www.seagate.com/images/suppor...5_family_1.gif
http://www.seagate.com/staticfiles/i...umpers_rev.jpg
http://www.seagate.com/images/suppor...sata_block.gif
http://www.seagate.com/images/suppor...ta_jumpers.gif
RPS or Reduced Power SpinUp is very useful when using a notebook SATA drive with a USB adapter and no power supply, using the jumper in the RPS position lowers the power load on spinup when you are using only the power provided by the USB port.
http://www.wdc.com/en/library/portable/2579-001116.pdf
Please check the manufacturers knowledge base for your own drive to make sure of the jumper settings for your drive.