title: MongoDB geo distance/radius to useful units
body: <p>I'm using MongoDB geospatial queries -- <code>$near</code>, <code>geoNear</code>, etc. -- and I'd like to know how to turn the <code>dis</code> result of the <code>geoNear</code> command as well as the <code>radius</code> argument for <code>$within</code> queries to/from readable units like miles or kilometers.</p>