I went through the Japanese sites as posted below in the "Mac/Clie" thread and found the link here:

http://www.iris.dti.ne.jp/~ymizu/macusb/index.html

It is towards the bottom of the page.

I guess this is a Beta2 release for OS 9.0.4, I have yet to try this myself. However I was told that as long as the Palm OS is above 3.5 it should have no problem IR synching with Macs.