WTFCNN allows you to compare different news websites with CNN US using a horizontal split screen format. You can also use it to compare any news website you want, to incite rivalries, and to explode the universe.
Feel free to use the WTFCNN source to create your own mashups. The code is licensed under the Creative Commons Attribution 3.0 United States License, so you can basically make whatever you want -- just link back to us.
Please email contact@wtfcnn.com when you've got it up and running. We'd love to check it out, and will gladly blog about you.