Web service Track

i had developed a web service which is to be used by web browser,window form and PDA. I want to track the records of the clients. Its means that i want to track in the web service whether a request came from a window form, browser or PDA.Can it possible with in a web service to handle this?
We want to identify the device from which the request is coming.
[360 byte] By [formanitefun] at [2007-11-19 10:00:31]