There is a school of thought that externally referencing Google for your js library helps lower load times and is the preferred method of inclusion. If the visitor has frequented another website calling the same file, it would be cached in the browser and forgo the 50-60kb download. While this is true, have you considered the risk of doing so? What if the unthinkable happens and Google has a hiccup. Well today was one of those what ifkind of days for Google, the googleapi servers (“http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js “) became unresponsive and hence so did some of our older applications. Interestingly enough, we had such a debate internally a while back and deduced that we would no longer reference externally hosted libraries for just that reason, thank god for meetings.
Moral of the story being, a savings of 60KB is not worth your application failing.