its like this. say a friend says he wants to build a system to enable smartphone turn by turn navigation indoors.. my first thought would be..apple/google/mall developers/nokia all have more millions than we have dollars and what have they done about it? why you? what advantage do you have over them? or what has changed in the circumstances or context to make this indoor navigation thing interesting? i guess thats a rather adversarial way to phrase things, but are questions i actually want to know the answers to..