Razer Hydra and Stand Up VR

I have been playing with the Razer Hydra with UDK and while it is quite simple to use them for a sit down VR application, I much prefer to stand up for FPS type VR games. So what are the options with the Razer Hydra?

I have seen the base mounted on top of your head in the Project Holodeck. So that would work OK if your players direction was mapped to the headtracker yaw, but what if you wanted to separate the players view from their direction of movement? Having the base on your head wouldn't work in this case, you would need it mounted on your torso.

Just wondering what others are doing with the Razer Hydra?