First of all your PalmPilot™™ has to actually support IR HotSyncs. This can be achieved through various means: Palm OS® 3.3 and higher include support for it; there is an IR enhancements package for older Palm OS® versions; IrLink from IsComplete apparently has the same capabilities. Check out the PalmOne web pages for more information.

Assuming your PalmPilot™™ now has PC HotSync support and it is setup to do IR HotSyncs (in the HotSync preferences on the PalmPilot™™), we can turn our attention to the PC you will be synchronization with. It needs an IR port. For laptops, this is trivial, desktop PCs may require some extra hardware.

Your Linux® kernel will need to support IR and the IRCOMM protocol. For stock Red Hat® systems, the following command should setup IR support (as root):

# modprobe ircomm

Other distributions should follow the IR-HOWTO. Once IR support in the kernel has been activated, you need to make devices for the IR ports. The IR-HOWTO suggests (as root):

# mknod
/dev/ircomm0 60 64 
# chmod
666 /dev/ircomm0

Next we need to start some daemons for IR services:

# irattach
/dev/ttySn
# irmanager
-d 0

Here /dev/ttySn is the serial port the IR port is using. n could be 0, 1, or some other number depending on your hardware setup. Follow the instructions in the IR-HOWTO for assistance (for desktop machines, it's usually a setting in the BIOS).

Once you've gotten this far, just make /dev/pilot point to /dev/ircomm0 and you're ready!

The IR-HOWTO and other useful information on using IR may be found at http://mobilix.org/howtos.html and http://mobilix.org/software/irda/.

Yes, you can. I don't have definitive information, but postings on the KPilot mailing-list have stated that you can point /dev/pilot to the USB device and everything will work fine.

No, not yet. Maybe later.