I've used an infra-red USB dongle. It was cheap on ebay, and it worked right out of the box. Since there are no cables, this "should" work with other Palm devices (and it does work with my Palm IIIxe as well as with my i300).

I use palm's desktop, set the com: port to the iRDA port. On the i300 I launch the HotSync application, select "IR to a PC/Handheld" and tap the icon in the middle.

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Frank