"The Psion 56K Travel Modem is a modem which you can get NOW and use with
ANY Pocket PC or any device that has an infrared port. The only apparent
disadvantage might be the batteries but the device seems power-efficient
enough and could last quite a while ("a while" being about an hour)."
FULL STORY @ ROJAKPOT (http://www.rojakpot.com/Reviews/Psion_56K/Psion_56K_01.htm)