Ignoring the old non-color screen and the $399 price tag, this PDA is actually pretty handy for people who work or play near water. The Meazura "Rugged Digital Assistant" conforms to IP67 standards so it's dust and water resistant.
PDA RDA also has a MZIO slot that fits CompactFlash cards. We can see this being useful for say, paramedics, who can't guarantee to not get blood on their PDAs in the course of the day. Also, there's the really clumsy pool cleaners.