Such a capsule recreation room appeared in the Moscow airport Sheremetyevo. They are not used yet, but are planned to be used by the end of 2012, when fully functional sleepboxes appear.
One hour in the sleepbox will cost 10 dollars. The capsule can be chosen for 1, 2 or 3 persons. There are a luggage compartment and Wi-Fi in it.
Do you like the idea of sleeping right in the airport?