PHP method for making page printer friendly

I am looking for a 'method' of making a page printer friendly. I have 'kinda' figured out how to do it by calling a script that then fread's a page and fixes it up .. but i have not been able to figure out how to do it on the current page. So .. how do you call a php script which can do this? doesn't really seem possible .. must be aone of those chicken and egg things <g> any ideas appreciated DSig David Tod Sigafoos