Here are the headers from wget:
--2013-01-01 17:03:48-- http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js
Resolving ajax.googleapis.com (ajax.googleapis.com)... 173.194.78.95, 2a00:1450:400c:c05::5f
Connecting to ajax.googleapis.com (ajax.googleapis.com)|173.194.78.95|:80... connected.
HTTP request sent, awaiting response...
HTTP/1.1 200 OK
Vary: Accept-Encoding
Content-Type: text/javascript; charset=UTF-8
Last-Modified: Mon, 02 Apr 2012 18:24:28 GMT
Date: Thu, 20 Dec 2012 19:07:24 GMT
Expires: Fri, 20 Dec 2013 19:07:24 GMT
X-Content-Type-Options: nosniff
Server: sffe
X-XSS-Protection: 1; mode=block
Cache-Control: public, max-age=31536000
Age: 1029384
Transfer-Encoding: chunked
Length: unspecified [text/javascript]
Saving to: ‘/dev/null’
[ <=> ] 93,868 --.-K/s in 0.1s
2013-01-01 17:03:48 (737 KB/s) - ‘/dev/null’ saved [93868]