It sounds like a bit of a nothing feature.

Perhaps it does at first blush, but when you read the specs on this chip you find out some interesting things which sets your mind wondering about applications.

First, the compass is a three plane compass, (three compasses in one) It can provide magnetic direction in three planes, X, Y, and Z (Think if it in aeronautical terms as Heading, Pitch, Role. Yaw can be deduced once you are motion by use of the GPS).

It can sense the orientation of the phone as it sits on a desk, or as you move it around in your hand or in your pocket. The accuracy is 1.4 degree steps in all three planes.

Because of the technology involved in magnetic sensing, the readings need to be adjusted for temperature, so the chip has a separate temperature sensor, which can be used to tell the local temp (inside the phone), from -30 to +90 degrees Centigrade, to within .4 degrees of accuracy.

This temperature data can be separately read out and used to invalidate your warranty or display the phones temp. If the chip is located away from the heat generating components in the phone (CPU and screen backlight), such as against the lower back cover of the phone, you also get a built in mini local weather station, or body heat sensor.

The phone will know its in your pocket as opposed to a purse or external case.

It can make all 4 of these measurements (XYZ+T) in 12.56ms starting from a power down state, and returning to power down automatically as soon as the measurement is complete, which translates into very good power conservation. Each measurement is automatically time stamped.

Some of this information would be redundant with the accelerometer, (which appears to operate in one plane only). But that is a good thing in that one sensor can be used to calibrate another. ("Swinging " the compass as you drive)

If the accelerometer says the top edge of the phone is down, but the compass says the top of the phone is up, the phone is falling - Fast. So what? Well this can be used to invalidate your warranty BEFORE it hits the ground, or as a WII like controller for games.

So thinking beyond the obvious Mapping application and Geotagging of photos, there are a lot of gaming applications that can be developed when you can sense not only roll (like the current phone) but also the exact direction,angle,tilt,upside,downside, of the phone.

Wire sensing, current measurement (is this 220 volt circuit hot?) can be done by measuring magnetic deflection when the phone is held close to a wire.

Turn by turn becomes more precise, because you don't have to be in motion for the GPS to sense heading.

Temperature readings can be collected and graphed.

The phone will know who you currently have a crush on by how warm your hand gets when she calls.

Throw in some clever APP developer to measure wind noise at the Mic as you swing the phone 360 degrees and you also get wind direction and speed estimates.

Really, don't dismiss this as a pointless sop to google street view. It has a lot of potential.

802.11n =]