Kris, I use the memory foam and Marg is right - it gets twisted. I also do not think it would be what you are looking for.
You need something like a wedge I think. That is thinner at the back and gets thicker as it reaches your head so it supports and lifts the entire back/neck/head at an angle.
How about these?
http://about.pricegrabber.com/search_get...about_heartburn
http://www.onlinesports.com/pages/I,MKM-...easy child-_-MKM-COR195
http://heartburn.about.com/b/2006/08/25/wedge-pillows.htm
