I finally got around to configuring my iMac last night (the desktop box that's replacing my 3-year old dual-processor FreeBSD box that started overheating).
One thing I didn't want to give up with this box was a real UNIX file system. So after kicking the tires a little, I reformatted it into two partitions -- one HFS+ and one UFS. I also unchecked the "Add MacOS 9 Drivers" on both partitions when setting them up. About half an hour later, when the Jaguar install was finished, I found that I didn't have a Classic environment.
Hooray! I've been trying to figure out how to install OS X without Classic. Previously, I wanted to do a simple upgrade to 10.2 because I didn't have a spare Mac (or a backup). Now that I have both, I'll probably reformat the iBook in the next few months.