World Map with D3.js

gistfile1.js

(function(window) {
  var data,
      xy = d3
            .geo
            .equirectangular()
            .scale($('#map_container').width())
            .translate([$('#map_container').width() / 2, $('#map_container').height() / 2]),
      path = d3
              .geo
              .path()
              .projection(xy),
      svg = d3
              .select('#map_container')
              .append('svg:svg'),
      countries = svg
                    .append('svg:g')
                    .attr('id', 'countries');


  /* World Map */
  countries.selectAll('path')
    .data(window.countries_data.features) // get the data here: https://gist.github.com/2969317
    .enter()
    .append('svg:path')
    .attr('d', path)
   .attr('fill', 'rgba(29,91,85,1)')
   .attr('stroke', 'rgba(29,91,85,1)')
   .attr('stroke-width', 1);

}(this);

Just came to double up @mittenchops request. Having a tough time comparing this to the D3 albers or mercator examples, especially in the case of the json this is using. Hoping for some more context.

You could optimize a little bit the script by reducing number of dom queries and assigning $('#map-container') to a local variable so you querythe DOM only once instead of 3 times.