Well, I found something that works...sorta.
The Palm Desktop software that came with my Visor (2.6) installed and seemed to "run." But any time I went to actually sync, it would get to the third and final step and then spit out a synchronization error (#-2804). Also, whenever I tried to run the HotSync Manager (or whatever it's called) I'd get the same error.
I uninstalled 2.6, and found an older version of Palm sync software on Palm's website that claimed to work on 68K Macs. It can be downloaded from:
<a href="http://palm.www.conxion.com/macdt10.hqx" target="_blank">Palm MacPac v1</a>
You can also get a small update for the conduit manager here:
<a href="http://palm.www.conxion.com/macconmgr.sit.hqx" target="_blank">Conduit Manager 1.01 update</a>
I got further with this software, and all seemed well, but I still got some errors during synchronization. As I really only need the hotsync feature to install software to the PDA, I went into the Pilot Desktop application and did the following:
Clicked on the HotSync menu item.
Clicked on Custom...
Changed the action for all the conduits to "Do Nothing," except for Install, which I left "Enabled."
Now during HotSync, it doesn't choke on all the Address Book, Calendar, etc. stuff, it just installs the software that you want.
Hope this helps other people with a PDA that might have an old Mac lying around and don't need all the bells and whistles.
(P.S. This is only a temporary solution for me until my USB cradle arrives...I plan on doing full synchronization with Palm Desktop 4.0 in OS X on my G4 Cube!)