Spin down hard disk: any suggestions?

[Paolo Pisati]

As the subject says i'm trying to spin down/turn off/
put in energy safe/etcetc automatically
my usb disk.

I'm running 5.x and the only way to reliably calm down 
my disk was to umount it.

The 'trick' was to use automount and periodically 
check & umount it, but i thought there should be better 
ways to handle it (or at least i hope so :). 
(from: "Fun With Automounting on FreeBSD" -
http://www.daemonnews.org/200202/automounting.html)

Any other ideas/suggestions?
How do you do it?
Any help from the recent ATA/SCSI/CAM/etcetc driver? 

It's quite annoying when your brand new USB disk starts getting
hotter and hotter cause the bloody usb case is too little and 
there's no air circulation/fan at all... 

Thanks.
-- 
Paolo