<http://schema.org/image>
<http://rack.2.mshcdn.com/media/ZgkyMDEyLzEyLzA0LzRjLzV0ZXJyaWZpY3R3LmNZTy5qcGcKcAl0aHVtYgkxMjAweDYyNyMKZQlqcGc/62886b46/ed6/5-terrific-twitter-research-tools-656084ccc1.jpg>
<http://mashable.com/2009/05/03/twitter-research-tools/>