Here is a short simple tip to read json output from curl in a neat formatted way:
Pipe the output to Python like this:
curl "http://url.to.call?args=hi" | python -mjson.tool
This will prettify the output and make json much more readable when testing webservices. It also validates the json, so if it contains errors you will get a warning.
It works with Python 2.6 and higher and you can find more info at the Python docs page.