http://www.linnovate.net/blog/drupal-openlayers-display-your-content-map
http://drupal.org/project/openlayers http://drupal.org/node/627816 (getting started)
http://drupal.org/node/911028 (using mapbox)
http://drupal.org/node/904898 (zoom to place with GeoTaxonomy)
http://mapbox.com/put-your-content-map-25-minutes-geo-enabled-blog-using...
http://drupal.org/node/904646 (openlayers WKT CCK field)
OpenLayers Examples
http://openlayers.org/dev/examples/ See the OpenLayers Example; layer switching controls and sample js file