done before, but not for gaming (Score 3, Informative)

The Navy's been working on a system similar to this for years. However, where this system is for gaming, theirs is for pilots, Seals, etc (anyone who might need more info than they can look at). Its not in full use yet, but the website is http://www.namrl.navy.mil/accel/tsas/. Since everything but the homepage is broken, here's a brief rundown: normal vest, pneumatically activated vibrating bumps (about 30 sewn into the vest, each about the size of a dime), air pumps, controller. Program the controller to activate the pumps based on whatever input you want (ie, where is and how far away is the ground, where is the enemy). Each pump is tied to one bump (vibro-tactile actuator, if you want to get all nerdy). With the right controller setup, you can fly blind, land in a snowstorm, or lose sight of an enemy without losing awareness of where they are.