I came to the conclusion in 2003 that a Bondi motherboard was just too sluggish and buggy to be worth the effort to recase it, so... unless you *really* specifically want to create a bookend, lunchpail, or abstract sculpture that runs OS 9 "okay" and OS X badly it's really hard to imagine it being worth the effort to recase one today. Not with G4 towers being essentially free. But each to their own.

Honestly the really discouraging thing about the Bondi motherboard was it's such an unusual shape and surprisingly bulky. (Being how it's actually a "board sandwich" with that metal CPU cage on top and that oddball power connector on the bottom.) I test-fitted quite a number of "interesting" small-footprint or slim cases, including an old router, a SUN Microsystems disk box, an old stereo, etc, and it wouldn't really fit in any of them. If I'm going to waste the space needed for a full-size PC case then I want something better than 233Mhz and two USB ports.