How to query posts with certain custom meta data, and output Post data

Trying using WP_Query() using the meta_query arguments.

Something like this:

<?php
$geotag_post_query_args = array(
    'meta_key' => 'latlng_readable'
);

$geotagged_posts = new WP_Query( $geotag_post_query_args );
?>

Now, $geotagged_posts is a query object, that should include all Posts that have the latlng_readable meta field. You can extract the $post data from this object the same as any other query object.