I'm still interested in fitting a bluetooth adaptor inside a Zaurus. I know I could (I guess) get a 3100, and replace the internal microdrive with a bluetooth CF adaptor and use a ROM image from a C1000.
I would steal the serial lines from the IRDA adaptor. Although someone did say that the 860's processor has a second serial port, it's not clear whether that's easily accessible without soldering onto the CPU!
I've not taken my 860 apart (yet!), but I have looked carefully at lots of photos, and I can't tell just how much room there is, but I am guessing it isn't going to be much. Can anyone give me a better idea?
Meanwhile, I found a few places with embedded bluetooth modules:
I have a contact at cambridge silicon radios I might ask too.