How precisely can I track distances using the iPhone accelerometer? Theoretically the accelerometers in the iPhone can be used to track distance using interpolation over time.

What is the estimated error for tracking distances between 1 and 10 meters?
Is there any iPhone app that work as a measuring tape?
From what I've heard, the iPhone accelerometer output is very noisy - most applications that utilize it for any sort of moderate precision work do a lot of filtering and output modification to smooth out the noise.  The iPhone can be placed flat on a table, and the accelerometer will still output a fair bit of data.  I imagine you could certainly use it to measure longer distances (>10m), but I probably wouldn't trust it for high resolution measurements.