The CirculaFloor is back !
From this article at BotJunkie :
A 5 meter square of area is sufficient for continuous movement in any direction. The tiles also incorporate lifts sufficient to replicate the feeling of climbing stairs… After you step up, the tile slowly descends, bringing you back to ground level in time to step up onto the next tile.
The original CirculaFloor system used magnets attached to the user’s shoes along with sensors in the tiles to figure out the direction of movement.