New Galaxy Nexus phone has a barometer, but what good is it?

Most people know that barometers have something to do with weather, but what good is having a barometer in your phone? According to BOSCH, it can and will be used for the following things:

BMP180 target applications

• Indoor navigation
• GPS-enhancement for dead-reckoning, slope detection, etc.
• Sport devices, e.g. altitude profile
• Weather forecast
• Vertical velocity indication (rise/sink speed)

The spec sheet for the BOSCH BMP180 barometer is here.

I'm looking forward to seeing what developers can create to take advantage of this new sensor. I'm still hoping that a wind speed sensor gets put into a smartphone sometime soon.