MySQL lat/long select by distance

geo-distance-select

SELECT field_geo_data_lat, field_geo_data_lon, SQRT(
    POW(69.1 * (field_geo_data_lat - [30.2707]), 2) +
    POW(69.1 * ([-97.7533] - field_geo_data_lon) * COS(latitude / 57.3), 2)) AS distance
FROM field_data_field_geo_data HAVING distance < 25 ORDER BY distance;

Note, this doesn't take into account the curvature of the Earth. So if you're guiding missiles, don't use this.