[thuh Freak]

i did a little more investigating, and i feel a bit sheepish now. according to the manpage for 'fs_usage', the 'W' we saw wasn't referring to a program, but to the time period on the other side (left side). 'W' means the time includes "wait time". so, you can move the /usr/bin/w.OUTOFTHEWAY back to /usr/bin/w, if you haven't already.

i looked up the 'update' program, and hark it is indeed a very heavy hitting file system call. in modern operating systems, storage media are typically orders of magnitude slower than RAM and the cpu. so, to avoid the horrendous delays when dealing with hard drives and disks, the OS takes a chunk of RAM and pretends like it is the hard drive, and periodically pushes that RAM back to the real physical media. ejecting or unmounting a disk will force this push (and since real data is often in RAM and may not yet be on disk, you'll often get warnings about properly ejecting a disk). well, enough of my rambling.

the 'update' call synchronizes the RAM fake drive and the real physical drive. If you suspect, or know, that some hard data is in RAM and not on disk, you can call 'update'. when it returns, your disks will be updated. it seems that periodically, the OS is calling update, to sync up the disks. two consecutive calls to update, in theory, won't actually touch the hd (the second time) since it should be all sync'd up. but, another program is still playing with the hard drive so its out of date again.

cupsd is the "Common Unix Printing System Daemon". a daemon, in computer science, is a program that runs in the background with no input or ouput. often, and in the case of cups, a server (server, here referring to a piece of software, not hardware) will be a daemon and will accept incoming connections from clients, then "fork" another program to handle all further communication with itself and the client. i don't know too much about the specifics of cups (as to why it would be in use so much, unless you have a document printing, or another computer attempting to access a printer through your computer). but, i know that you can turn it off. i'm more of a command line guy, and from what i remember its not easy or obvious to do what i'm about to describe via the GUI. also, if your printer(s) use cups, you won't want to do the following. iirc, you'll need cups if you are sharing your printer with more than one computer, accessing a printer through another cups, or if your printer directly needs cups, or, of course, if you remember a deliberate requirement somewhere in the specs from your printer for cups. worst case scenario, we notice that you're printer does require cups, and we turn it back on.

in terminal, try the following:
sed 's,\(CUPS=-\).*\(-\),\1NO\2,' /etc/hostconfig > /tmp/newconfig
sudo mv /tmp/newconfig /etc/hostconfig
(c+p the above, to make sure you get the quoting, spacing and greater than symbol correct)

if you had opened /etc/hostconfig before hand, you'd notice that there was a line with "CUPS=-YES-" (or possibly "CUPS=-AUTOMATIC-"), and afterward it will be "CUPS=-NO-". you'll have to restart for it to take effect. after coming up from a restart, i recommend you try out your printer and make sure it works. if it doesn't work, we can revert back with the following (in terminal again).
sed 's,\(CUPS=-\).*\(-\),\1YES\2,' /etc/hostconfig > /tmp/newconfig
sudo mv /tmp/newconfig /etc/hostconfig

assuming that your printer works with cups off, you can try idling again, and see if the hdd spins down. hopefully we're a little closer.