This is pretty interesting, and fairly relevant considering the Super Bowl is later today. The folks over at Impakt Protective have come up with a g-force sensor that fits inside a helmet, and measures the impact a player sustains from a tackle or collision.
If a player is hit too hard, the sensor, which is appropriately named the Shockbox, will send a color-coded alert to a designated iPhone or other mobile device. Impakt is hoping that this will help curb the growing rate of sports-related head injuries...