From Thanos 6DOF Motion Simulator Electronics blog:

Lately we see more and better DIY 6DOF platforms being build. The community is growing strong and the interest in 6DOF systems is bigger than ever. Its the only way to provide full immersion for motion simulation at the moment, that combined with other new technologies like the oculus rift or fully enclosed detailed cockpits can really make the difference. The times that desktop racers or flight enthusiasts were enjoying their simulation games or training for the real thing is past without return. Even older motion systems that provide 2DOF (seat movers) or 3DOF platforms are now the past, offering too little to the immersion of gaming... (more projects)