This is not a party idea, but an invitation idea for kids.
I go to price club or BJ's and get a box of 36 regular size Hershey bars and I carefully take off the first label and open it up and use it for a pattern. I measure it and then i print up my own labels on colored copy paper on my computer that say Lisa's Birthday Party and all the information right on the paper, than I cut it to fit the chocolate bar and glue stick the new label on them, they are easy to do and look great, I get so many compliments on them, this is not an original idea, however, It is easier to do yourself than most people think. The labels just slide right off. My daughter is the most popular kid in school when it comes time to hand out the chocolate bar invitations to her whole class.