To answer one part of the question, the number is the radius of 68% confidence, meaning that there is a 68% chance that the true location is within that radius of the measured point in meters. Assuming that errors are normally distributed (which, as the docs say, is not necessarily true), that means that this is one standard deviation. For example, if Location.getAccuracy returns 10, then there’s a 68% chance the true location of the device is within 10 meters of the reported coordinates.
http://developer.android.com/reference/android/location/Location.html#getAccuracy()