XML Guestbook with PHP

I like the Guest book, example. Pretty neat. I don’t know how much of a pain this would be to do, but what if I wanted to allow each guest to upload an image of themselves to go with there notes? IS that possible and if so,

what code would I need to add to the current ** [font=Verdana][size=4][color=#003366]XML Guestbook[/color][/size][/font]** [font=Verdana][size=4][color=#003366]with PHP tutorial

Thanks a bunch…