There have been a few posts about flat heads recently so here is something I found on the internet.

Its called a Sleepcurve Mattress and its supposed to help correct Plagiocephaly.

I am going to get one as soon as possible.

ETA....just wanted to say that I am a big fan of Cranial Osteopathy for babies, I am sure that there are some on Long Island, it has really helped with settling my little boys temperament and it great for colicky babies. But also, babies with flat heads benefit greatly as it relaxes the plates in their skulls