What would be a good way to attempt to load the hosted jQuery at Google (or other Google hosted libs), but load my copy of jQuery if the Google attempt fails?
The inability to load the resource from an external data store beyond your control is difficult. Looking for missing functions is totally fallacious as a means to avoid suffering a timeout, as described herein:
http://www.tech-101.com/support/topic/4499-issues-using-a-cdn/