This is something I give out on Valentine's Day every year. I photocopy the document double-sided, and add my name and tape a piece of candy on the back. Many students accept it gratefully but end up throwing it out after they eat the candy. Some students take the time to do the code on the front out of curiosity. If they do, they find that it spells out, "Submit this to me outside of class for a bonus point." (There are 4 varieties of this message to cut down on the possibility of cheating.) It's a fun tradition!
I have included an editable Word document version so you can change the message or otherwise adjust as desired, as well as a PDF version.