Hey I figured it out.
I installed the Sony Desktop software on a notebook then copied the two Clie files from the USB_Driver folder. The 2 files were CLSH00DA.inf and CLIEUSBE.CAT. The third file was the PALMUSBD.SYS file, and a newer version was already in the folder used by my Palm M505.
I just did a HotSync from the Clie when it was attached to the USB port, and when it did the "Found New Hardware" routine, I pointed it to the USB_Drivers folder, and presto it loaded the driver.
Now my system will HotSync to both the M505 and the Clie NX70v/u via the USB port. The Clie can also HotSync via the network too, which is really cool.
I hope this may help out someone else in the future.
- Tim -