Some Google employees have mentioned on the web that the barometers are there to speed up GPS. I understand that GPS is slow when it's alone, but when it has as

Some Google employees have mentioned on the web that the barometers are there to speed up GPS. I understand that GPS is slow when it's alone, but when it has assistance on location guesses it can be much faster. So they can use cell tower triangulation / WiFi spots for your latitude and longitude, and they can get a rough estimate of your altitude through the barometer.