any picture can be used i think just have to be if i remember correctly a .png file at a certain size but yes go onto the website MR BEN mentioned and a few others and you can download loads. Make a file in library/ app support/logic/Images/Icons
im not sure if images or icons is there but you to make the folder. then just drag your png files into there.
you allready have some pics of the virus in library/audio/midi devices/access music/images
there is a big collection on the logic forum somewhere also
http://www.logicprohelp.com/forums.php