Create a SoundCloud widget from the id passed in the url

gistfile1.js

// You will need jQuery to be available on your page
// the widget will be written into HTML element with id="player" or some other DOM element that $playerContainer will point to
// the url format should be http://example.com/mytracks?track_id=3223234 or http://example.com/mytracks?track_url=http://soundcloud.com/matas/hobnotropic
$(function(){
  var params = location.search,
      trackId = (params.match(/track_id=(\d+)/)||[])[1],
      trackUrl = (params.match(/track_url=(.+?)(&|$)/)||[])[1],
      $playerContainer = $('#player');
  if (trackId) {
    trackUrl = 'http://api.soundcloud.com/tracks/' + trackId;
  }
  if (trackUrl) {
      $.getJSON('http://soundcloud.com/oembed?format=js&url=' + trackUrl + '&iframe=true&auto_play=true&callback=?', function(response){
      $playerContainer.html(response.html);
    });
  }
});