@NogDogMay 14.2006 — #If it's a question of mobile devices accessing PHP documents from a web server, then you don't really do anything different with regard to PHP programming. However, you may need to reconsider your web page structure and layout as well as its CSS styling, to make the output usable/readable on such devices.
If the device sends the necessary HTTP headers for the server to detect such information, then you could use some if/else or switch structures to customize what output is sent as well as what stylesheet is used, depending on the type of browser. For instance, see the info on [url=http://us3.php.net/manual/en/function.get-browser.php]the get_browser() function[/url].