First of all, great plugin. JSON is so much more fun to work with than XML. :)
I'm having a bit of trouble with one of my queries, though. I'm trying to return results that:
* Are part of a certain custom post type ("event")
* Have a custom field with a date that is greater than or equal to the one passed to the JSON API.
I think I've got it figured out, but the JSON API plugin is only returning three results...while a similar query returns six using query_posts(). I don't know if I've got an issue with the URL I put together or if there's a problem with the plugin's post type handling.