html snippet that calls jQuery 2+ for modern browsers or jQuery 1.10+ for old IE, from CDN and with local fallback.
I just combined two other snippets to create this version.
Double check jQuery CDNs for latest files: https://developers.google.com/speed/libraries/devguide#jquery
jQuery 2 with less than IE9 fallback => http://blog.jquery.com/2013/03/01/jquery-2-0-beta-2-released/
jQuery CDN with local fallback => http://css-tricks.com/snippets/jquery/fallback-for-cdn-hosted-jquery/