I can't tell if your you're joking or not. Linking to the latest version is a very nice way to break your app automatically.

You can even drop the http: part, like this:

    <script src="//jquery.js/latest"></script>

Or use Content-Type negotiation. (please note, I do understand that this proposal is basically DOA)

Nah, too much typing. Maybe if you got rid of jquery.com. It's not even a company!