Arghh… Another obstacle…
How to put the USB drive into stand-by mode, so it will spin down when not in use.

http://www.ruzee.com/blog/2006/01/usb-storage-standby-with-linux/
http://forum.openwrt.org/viewtopic.php?pid=37514
http://www.ruzee.com/blog/?page_id=32
http://ask.metafilter.com/mefi/36580

Linux (Debian) Configuration Notes

Figured it out.
Well at least I found one command that will work for my HD+Drive enclosure combo.
sg_start –pc=3 /dev/sdc
It powers the drive down to standby mode. And when it needs to be accessed, it spins back up again.
I just need to put this in some sort of a script that will ensure that the drive has not been accessed in a while, and this drive is ready to be my backup drive, which will likely be accessed once a week to make system backups to it.
The page that helped was this:
http://www.nslu2-linux.org/wiki/FAQ/SpinDownUSBHarddisks
so I’m guessing that even if the drive has only 10,000spin ups left (from their 40,000-50,000 spinups when they are new) which is unlikely, but still, and I access the drive 3 times a day, I should still get almost 10 years of life left… which is plenty.