if you go to the wondertouch site, you have lot’s of emitters to download, they come in librarys after you unzip them you put the files in the emitter folder in the directeory where you installed particle illusion. After that when you open the program bottom right you have the current library of emitters yur using, press the mouse right button, quick library or open library and choose the one you early putted on the emitter folder =)
Hope it helps.