I was creating some JSON data with PHP to pass to an iPhone app today and I found a great online JSON validation tool: JSONLint: The JSON Validator.
Just plunk your JSON string into the window and press the validate button. Voila, not only are you told if your JSON string is valid but it also arranges your JSON data in an easily readable hierarchy. The JSON Validator was made and shared by the good folks at lab.ac9.com.Thank you arc90!

