I love the two crayons idea for representing the child's second birthday!
Also, you could make "color me cards" for the kids as favors...(Color me cards are ones where you stamp them in black open images, and include crayons for the kids to color in on their own to make the cards more from them...so many people have images of these in their galleries but here is a
link to ones I made a long time ago if that helps!)
Kelle