http://vk.com/audio total duration of searched tracks

gistfile1.js

var total_time = function() {
  var durs_sourse = [], total = 0;
  $('.duration').each(function(i,v){ durs_sourse.push( $(v).html() ); })

  for(v in durs_sourse) {
    total += parseInt(durs_sourse[v].split(':')[0]*60) + parseInt(durs_sourse[v].split(':')[1])
  }

  return 'всего ' + (total/(60*60)).toFixed() + ' час. ' +  (total%(60)) + ' мин.';
}

total_time();

this need jquery