Unpadded Seats In Coach - Aching Posteriors

Has anyone found a good solution to easing the discomfort and "seatitis" caused by the thinly padded seats in most Coach class transatlantic flights? I know you have to get up and walk around a little bit to get the circulation going, but I am wondering whether anyone has discovered an inflatable cushion device, pad, etc. to help alleviate the problem. We have friends who do not want to accompany us on a European cruise because they cannot handle the 8-9 hours of an aching posterior, and business class is outrageously costly....HELP!

Not promoting any one site, but here are three examples of travel "seat pillows" that are available online. I'd suggest a more thorough online search, but here's at least a start. GSeat Best Seat Seat Cushion

For those eastbound overnight overseas flights..... make your nest in this.

http://www.magellans.com/store/In_Flight_Comfort___PillowsIF430?Args=