art cards are really fun. they are like baseball cards, except you make your own! you cut out a piece of paper (3 1/2"-2 1/2") an do whatever type of art you want on it, then find someone to trade with. my family has a home school group that I trade with all the time. there are quite a few different styles.
For the past few weeks I've been spending all ( okay not all. most.) of my spare time working on art cards.