reqwest('path/to/html', function (resp) {
  Q('#content').html(resp);
});

reqwest({
  url: 'path/to/json',
  type: 'json',
  method: 'post',
  success: function (resp) {
    Q('#content').html(resp.content);
  },
  failure: function (err) { }
});

reqwest({
  url: 'path/to/data.jsonp?callback=?',
  type: 'jsonp',
  success: function (resp) {
    Q('#content').html(resp.content);
  }
});

reqwest({
  url: 'path/to/data.jsonp?foo=bar',
  type: 'jsonp',
  jsonpCallback: 'foo',
  success: function (resp) {
    Q('#content').html(resp.content);
  }
});