Iphone4 and GPS alternatives

Question

provided GPS will not work precisely in closed environment like rooms etc,I m interested to know whether Accelerometer can be used to find the position of object relative to certain point? If not then what other technology iphone4 provides to cater it?

Thanks

Answer 1

The accelerometer cannot reliably provide location information, even with the aid of the gyroscope. GPS is the best you are likely to get.

OTOH, work-arounds abound in the augmented-reality space. Consider the ARDefender game.