I wanted to be able to sync to my palm computer without the hassle of plugging directly into the USB every time. (also there seems to be a bug when using the direct USB cable to Linux).
I thought Infrared would be the best option as I could leave it plugged in all the time and there are less security issues than wi-fi or bluetooth.
I decided to get this device, although expensive, it came with a cable and the postage was free.
PC: Linux SuSE 10.0 running on this hardware.
Palm: Lifedrive system v.5.4.8
USB/IrDA bridge: Belkin F5U235QEA (should apply to similar devices with Sigmatel STIr 4200 chip)
IrDA is a standard from the 'Infrared Data Association'. This has different modes such as SIR and FIR, for more information see this page.
Security access to port
By default only root users can access this port, thanks to orankelium for explaining how to give other users access.
Connecting to the Palm
This is explained here.