Feel free to offer corrections, but I believe the original iBook doesn't suffer from the 8GB limit, despite it being so mentioned in Apple's KB article.
I picked up an original 300/32/3 ugly clamshell recently having always wanted one.
Digging through parts I had laying around I put a 40gb 7200 rpm drive in. Using a modified Tiger install disk (bypasses hardware check, no need for Xpost facto) I booted and started installing, then remembered the 8gb limit.
I created three partitions, 8gb, and two more. The last 15gb one I installed tiger into, and it booted! It was entirely outside of the first 8gb. It also didn't complain about an unsupported partition.
I then wiped the partition and installed OS 9.2 instead, again in a partition that is 15 gb in size on the end of the drive. It booted and worked faultlessly.
So I've come to the conclusion that the original iBook doesn't have this limit.
Note the drive was partitioned using Tiger's disk utility, which may have some bearing, and also was running the last firmware update Apple made.
I've experienced the 8GB limit before on original iMac and beige G3, so I know the symptoms, but this iBook seems immune.
The original iBooks didn't have the same type of firmware that the iMacs had. The iBook clamshells also came out at the time of the multi-colored iMacs which means the limitation didn't apply even at that time. Once the multicolored ones came out, that limitation was removed altogether. It was pretty much only on the old-world firmware and the original iMac (Bondi).
But thanks for sharing that with us!
Also, remember there is STILL one limitation that all macs prior to probably 2001 have, and that's the 128GB Limit on HDDs. I think it took till the iBook G3 700Mhz before it was replaced with the 48-bit LBA on the iBooks and the G4 PowerBook Ti 533/667Mhz before it was abolished on the PowerBooks.