Hello,

> > Any other info you need, or things you would like me to try, just let
> > me know. I got the machine basically for free, and it's just another
> > thing to play with.

> I think you're stuck with the 603. There are a couple of Umax 603
> machines with a ZIF socket but I think they were the only ones.

Just thinking... correct me if I'm wrong.
There are CPU upgrades that fit into the L2 cache slot for lots of different PowerPC-based machines, not only Macs, my PowerStack II for instance has such a thing mentioned in the manual and the BeBox developer notes say that the chipset they used could drive either a CPU and a cache or two CPUs. The one for the PowerStack was meant to be an additional CPU, not an upgrade though.
Anyway, I think the old world Macintosh chipsets supports (at least) two CPUs out of the box and that's why these things work at all - now we only need to tell OF which one to enable or figure out what MacOS does to run on the G3. 

Adam - after running NetBSD, does MacOS use the G3 the first time it boots or does it need a reset in between?

have fun
Michael