Upgrade Julie's G3 laptop to 768 MB of RAM, and push the OS from Panther to Tiger
Upgrading the RAM was fairly painless. I bought a 512 MB stick from the good folks at canadaram.com (this older type of RAM is hard to find, so a big thumbs up to the CanadaRAM crew for having it on hand). Installation was also aided by the step-by-step instructions at ifixit.com. After a reboot, 768 MB shows up on the system info screen. Awesome.
Part two was a lot more complicated. I was originally inspired by this article at lifehacker.com, which suggested using an older iPod as a installation drive for Leopard (I presumed Tiger would follow the same process). As I have a 20 GB model handy, I naively expected this to work perfectly. My first sticking point was that my copy of Tiger (the one that came with my MacBook Pro) was tied to the hardware, and could not be used to install on Julie's G3 iBook laptop, or anything else that wasn't a Macbook Pro.
I managed to track down a retail copy of the Tiger (10.4) installation DVD, but one of the key problems is that Julie's iBook doesn't have a DVD drive. The lifehacker article shows you how to get around this problem by creating an image of the DVD (on my MacBook), then erasing the iPod and copying that image to the iPod so that the iBook can use it just like a DVD drive. This worked great, except that the older 10.2 version of OS X on the iBook didn't have the "Disk Utility" to allow me to define which disk (the iBook hard drive or the iPod) should be used as the start-up boot drive.
The solution was to start up the iBook (with the iPod plugged in) while holding down the Apple and c keys. This made the iBook boot off an external device and showed me the Tiger installation menu. From there, I was able to install Tiger directly on the laptop in about 30 minutes.
Julie seems to be really happy with the new OS and the responsiveness that an extra 512 MB of RAM brings to her laptop. One resolution down, many more to go.