Basic Twitter object, demo at the bottom (require jQuery here but could also write your own Ajax function). This should work w/ all Twitter APIs which do not require authentification.

gistfile1.js

var Twitter = {
  version: '1.0',
  apiUrl: 'http://api.twitter.com',
  apiVersion: '1',
  api: function(endpoint, options, callback) {
    var fullUrl = this.apiUrl + '/' + this.apiVersion + '/' + endpoint + '.json';
    $.ajax({
      async: true,
      url: fullUrl,
      data: options.data,
      dataType: 'jsonp',
      success: function(response, status, xhr) {
        callback(response);
      },
      error: function(xhr, status, error) {
        console.log(error);
      }
    });
  }
};

var TwitterHelper = {
  htmlize: function(tweet) {
    // replace url w/ links
    tweet = tweet.replace(/(\b(https?|ftp|file):\/\/[-A-Z0-9+&@#\/%?=~_|!:,.;]*[-A-Z0-9+&@#\/%=~_|])/gi, '<a href="$&" target="_blank">$&</a>');
    // replace hashtags w/ links
    tweet = tweet.replace(/#(\w+)/g, '<a href="http://search.twitter.com/search?q=%23$1" target="_blank">#$1</a>');
    // replace @username w/ links
    tweet = tweet.replace(/@(\w+)/g, '<a href="http://twitter.com/$1" target="_blank">@$1</a>');
    // return HTMLized tweet
    return tweet;
  },
  timediff: function(timestamp, created_at) {
    // Time constants
    var second = 1000;
    var minute = second * 60;
    var hour = minute * 60;
    var day = hour * 24;
    var week = day * 7;

    // Timediff
    timediff = timestamp - created_at;

    // Create timestring
    if (timediff < second * 7)
      return 'right now';
    if (timediff < minute)
      return Math.floor(timediff / second) + ' seconds ago';
    if (timediff < minute * 2)
      return 'about a minute ago';
    if (timediff < hour)
      return Math.floor(timediff / minute) + ' minutes ago';
    if (timediff < hour * 2)
      return 'about an hour ago';
    if (timediff < day)
      return Math.floor(timediff / hour) + ' hours ago';
    if (timediff > day && timediff < day * 2)
      return 'yesterday';
    if (timediff < week * 52)
      return Math.floor(timediff / day) + ' days ago';
    else
      return 'over a year ago';
  }
};

// Demo usage
Twitter.api('statuses/user_timeline', { data: 'screen_name=keeguon&count=50&include_rts=true' }, function(response) {
  // variables
  var limit = 10;
  var timeline = '';
  var now = new Date();
  // tweet loop
  for(var i = 0; i < response.length; i++) {
    if (!limit) break;
    if (response[i].in_reply_to_screen_name || response[i].in_reply_to_status_id || response[i].in_reply_to_user_id) { continue; }
    else {
      var tweet = '';
      var created_at = new Date(response[i].created_at);
      tweet += '<div class="tweet">';
      tweet += '<p class="text">'+TwitterHelper.htmlize(response[i].text)+'</p>';
      tweet += '<p class="meta">'+TwitterHelper.timediff(now, created_at)+'</p>';
      tweet += '</div>';
      tweet += '<hr />';
      timeline+=tweet;
      limit--;
    }
  }
  // changing the html
  $('div.timeline').html(timeline);
});