Is there any publicly accessible JSON data source to test with real world data?

Twitter has a public API which returns JSON, for example -

A GET request to:

https://api.twitter.com/1/statuses/user_timeline.json?include_entities=true&include_rts=true&screen_name=mralexgray&count=1,

EDIT: Removed due to twitter restricting their API with OAUTH requirements...

{"errors": [{"message": "The Twitter REST API v1 is no longer active. Please migrate to API v1.1. https://dev.twitter.com/docs/api/1.1/overview.", "code": 68}]}

Replacing it with a simple example of the Github API - that returns a tree, of in this case, my repositories...

https://api.github.com/users/mralexgray/repos

I won't include the output, as it's long.. (returns 30 repos at a time) ... But here is proof of it's tree-ed-ness.

JSON Test has some

try its free and has other features too.

http://www.jsontest.com/