Micosoft:
http://www.asp.net/ajaxlibrary/cdn.ashx
<script src="http://ajax.aspnetcdn.com/ajax/jquery/jquery-1.5.js" type="text/javascript"></script>
<script type="text/javascript"> </script>
Google CDN:
http://code.google.com/apis/libraries/devguide.html#jquery
Comparison:
Some of opinions in following article is out of date.
http://stackoverflow.com/questions/1447184/microsoft-cdn-for-jquery-or-google-cdn
