<script type="text/javascript" src="[url]http://openlayers.org/api/OpenLayers.js[/url]"></script>
    <script type="text/javascript">
      var map, layer;
      var proj_4326 = new OpenLayers.Projection("EPSG:4326");
      var proj_900913 = new OpenLayers.Projection("EPSG:900913");
      var steps = 90000;
      var distance = steps*0.75;

      function init() {
        origin = new OpenLayers.Geometry.Point(6.60, 46.56);
        origin.transform(proj_4326, proj_900913);

        map = new OpenLayers.Map('map', {displayProjection: proj_4326, controls:[new OpenLayers.Control.Navigation] } );
        //map = new OpenLayers.Map('map', {displayProjection: proj_4326, controls:[] } );
        layer = new OpenLayers.Layer.OSM();
        map.addLayer(layer);
        //map.setCenter(new OpenLayers.LonLat(7.59, 46.66).transform(proj_4326, proj_900913), 7);
        map.setCenter(new OpenLayers.LonLat(6.60, 46.56).transform(proj_4326, proj_900913), 7);

        createCircle();


        map.events.on({zoomend: createCircle });
      }

      function createCircle() {
        map.setCenter(new OpenLayers.LonLat(6.60, 46.56).transform(proj_4326, proj_900913));
        var radius = distance/map.resolution;
        var myStyles = new OpenLayers.StyleMap({
          "default": new OpenLayers.Style({
            pointRadius: radius,
            fillColor: "#ffcc66",
            fillOpacity: 0.3,
            strokeColor: "#ff9933",
            strokeWidth: 2,
            graphicZIndex: 1
          })
        });

        var circus = new OpenLayers.Layer.Vector("Points", {
            styleMap: myStyles
        });

        circus.addFeatures(new OpenLayers.Feature.Vector(origin));
        map.addLayer(circus);
      }
    </script>

proxy_cache_path  /home/tilecache  levels=1:2:2   keys_zone=tilecache:1536m;

server {
  listen 94.23.198.39:80;
  server_name toto.internux.ch;

  access_log  /var/log/nginx/tiles_access.log main;
  error_log   /var/log/nginx/tiles_error.log info;

  keepalive_timeout 15;
  proxy_ignore_client_abort on;
  proxy_set_header  X-Real-IP  $remote_addr;
  proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
  proxy_set_header Host $http_host;
  proxy_set_header "ENABLE_X_ACCEL_REDIRECT" "true";

  location / {
    proxy_pass        [url]http://tile.openstreetmap.org/[/url] ;
    proxy_cache       tilecache;
    proxy_cache_key "$scheme$host$request_uri";
    proxy_cache_valid  200 302  7d;
    proxy_cache_valid  404      1m;
  }
}

(...)
Latitude: N 46° 27' 28.82
Longitude: E 6° 51' 13.76
Altitude: 4294967248.00 m
(...)