Hi, If you are going to implemet this using PDA & smart phones, the work is less I guess, cause these types have a web browser which can be used to brows your existing web application, or else you can create a J2ME application where it connects to the webserver via a web service, servlet/jsp and get the information. You can try our nokia emulator for J2ME to test these things or else go for Palm or Blackberry emulator.
Hope this is sufficient enough, regards.
SCJP 1.4, SCMAD 1.0<br />SCWCD, SCBCD (in progress)
subject: Converting web applications to mobile devices