the api should simply ignore any parameter it doesn't understand instead of throwing an error. For example jquery will append _=randomNumber to prevent caching of jsonp by the browser. This feature breaks that.
The jsonp callback should be 'callback' not 'jsonp' there is no reason you can't have both, but almost every single site that uses jsonp uses callback as the parameter, using something weird prevents people from easily making apps.
To see this library in action I created a couple of examples:
This is a table with on the left an explanation of how the right cell is defined.
http://pad.human.cornell.edu/Unlisted/ACS5API/Example1.html... more »