Very neat technology, and I think it could be of value in the developing world and sparsely populated areas, but is there that much need for this data in many parts of, say, the US or Europe? Here in San Francisco, I've got highly accurate weather stations at SFO and OAK, plus dozens of other stations on Weather Underground around the city. The variability of these readings over, say, 10 miles is quite low. Are there specific ways in which a more dense grid of barometric pressure measurements can give us further insight into weather patterns?
This would be a great augment in areas where the density of observations stations is much lower. Wind speed, which does vary a lot more due to terrain and structures, would be neat to map this way, but it's hard to measure the wind through our pockets on cell phones.