Seeing as how you haven't gotten any responses, combined with my own experiences getting OS X running on beige G3s this summer, I'm inclined to tell you that there is not a floppy drive hack for OS X, and that there probably isn't one forthcoming. I once saw one posted on the Apple Discussion Boards, and it did not work as advertised. Frankly, while being able to use a floppy drive would be nice, the floppy disk is dead as a storage and transfer medium. Better to get a SCSI Zip for your G3 (if you don't already have one).
Also, when I find myself needing floppy compatablility, it's really not that much of a hassle to reboot into Classic, grab what you need, and boot back into X. That, if nothing else, is a great reason to keep our old beige G3s as dual-boot rigs.