C.
We've travelled a lot with our son - now 14 months - as a lap child. Bring ID for your baby. Our son loves food and books, so we packed tons of snacks, favorite stuffed animal/blanket and books. Even popped in a Baby Einstien DVD in our laptop when grounded for 5 hours when returning from an international destination gone awry. Bring whatever your child really likes. We take off his shoes to minimize the impact of the kicking on the chair in front of us and encourage him to drink fluid on the ascent to keep his ears from clogging up.
Best of luck.