jQuery 1.2 introduced JSONP support, but on initial read of the release notes, I wasn't completely sure what it was - so for anyone else that might want the Dr Seuss explanation. JSONP is script tag injection, passing the response from the server in to a user specified function

I recently came across a funny bug where I was executing an AJAX method and the response was empty. I check the server side and I know that my particular query is returning a result, but thanks to Firebug I can see it's failing in the browser. So there was something definitely amiss.