An example of how to consume the JSON data from your Sinatra Twitter app. This is dependent upon jQuery. *Untested*

app.rb

get '/tweets.json' do
  if request.referrer == "http://example.com/blog/"
    jsonp @@twitter_client.home_timeline.map(&:attrs).first(5)
  else
    status 401
  end
end

fetcher.js

$.getJSON('http://pathtoyoursinatratwitterapp.com/tweets.json?callback=?').done(function(data) {
  $.each(data, function(index, value) {
    console.log(value); // Should output your tweet obj to inspect
    // Some DOM manipulation here ex: $('<li>').text(value.text);
  });
});