This one I actually bought on a whim, almost exactly the way I did with my ThinkPad. This one was driven by a vision of the iBook-wielding coffee shop hipster writing epic novels and slam poetry (though to be fair, this is NOT a Clamshell iBook, and I prefer it that way). I had to purchase a new battery because the one that came with it did not hold a charge at all, even after charging for days on end (and neither did the first replacement battery which was just as bad), and also some extra RAM, as I believe it is the very lowest spec that was on offer that year. It was the first iBook in a Dual USB chassis with the "Snow" design language. A 500MHz processor, 64MB of RAM, a 10GB hard drive from stock, and a CD-ROM optical drive. Using MS Word on it made the GPU so hot through the bottom casing it was uncomfortable to touch. I assumed this was because the bottom shielding wasn't there to act as a heat spreader, so I jerry-rigged something up and it runs much cooler now.
I'm currently using it as something of an e-Typewriter with MS Word for Mac 2001 and 2004, depending on which OS I'm booted into at the moment (true coffee shop hipster moments), and to play classic games both new-to-me and nostalgic, such as Quake, Diablo II, Warcraft II, and Riven!
Update I, June 23rd, 2023: SO ON WEDNESDAY SOMEONE APPROACHED ME TO COMPLIMENT MY BABY.
I take my G3 iBook places to write someplace other than my house, it helps keep the creative juices flowing, I find. So I take it to work with me on days I know I have time to hang out before my shift. This lady came up to compliment my laptop. I think she was wearing a DC Comics tee shirt, had a little bit of salt and pepper going in her short dark hair, and said "I just wanted to say, that laptop is awesome."
We talked about how old it was, I mentioned my other laptops, she asked if I've done anything to it, and we briefly talked about how Apple products have stopped beng upgradeable, especially starting around 2013 when the Retina models started to come out, making nothing but the SSD and Wi-Fi cards removable when in the 2012 model still had RAM upgrades possble. And now, you can't really do anything except batteries in the Macs without surface mounted components beng swapped around.
The entire interaction took a few minutes at most, but it made my entire day and validated every bit of time, money, and energy that I've spent on these things.
Specs:
Cost to me: $89