To Use a CDN for JavaScript or Not

If we use Google’s JavaScript Library CDN, we are asking the majority of our website visitors (who don’t have jQuery already cached) to take a 1/3 of a second penalty (the time to connection to Google’s CDN) to potentially save a minority of our website visitors (those who do have a cached copy of jQuery) 1/3 of a second (the length of time to download jQuery 1.3.2 over a 768kps connection). That does not make sense

(from Should You Use JavaScript Library CDNs?).