The SeatCushion by Tempur-Pedic
Product Review (submitted on June 4, 2010):
I have a desk job so I'm in my office chair about 9 hrs a day. I am 5 months pregnant and started noticing pain in my hips and tailbone the first day back at work after a 4-day weekend off. I picked up the tempurpedic cushion and now my hips no longer ache and my tailbone has a nice cushion-y place to sit all day! Love it and highly recommend it. It doesn't have the tailbone cut out, but still there's so much give in this cushion that it serves the same purpose.