So it looks like I'm going to have to go through the painful experience of replacing an iBook hard drive. It seems that my wife's iBook (which used to be mine) has had its drive fail (Disk Utility reports the S.M.A.R.T. status as "Failing").

I was actually just planning on sending it to Apple for repair, but I can't, for the life of me, figure out how to (!). A call to the 1-800-APL-CARE number sent me through a maze of separate automated menu systems from which I briefly emerged at one point to speak to an actual human, who unfortunately plunged me back into the maze. So I gave up and ordered a Hitachi 60GB 7200 RPM drive from Tiger Direct for $250 CDN with tax and shipping.

There are several step-by-step guides for replacing iBook drives - I'm following this one: Replacing the hard drive of a G4 iBook 800Mhz and recovering of the built-in mike.. I expect to spend most of a day and all of my patience doing this.

A useful tip, by the way:

Even though there are some pretty elaborate tools out there for keeping organized, I still find myself using Stickies constantly. It's always been a bit of a pain scrolling them though, so I was interested in this article from Macworld (which ends up working quite well):
Macworld: Mac OS X Hints: Scrollable Stickies