A WebmasterWorld thread discusses methods of speeding up the page load of a page that has Google AdSense on it. Sometimes, because of the ads are called from a different server, it may make the page of the site appear to load slower, when in reality, it is the ads that are slowing down the page load times. So what can you do to speed it up?
WebmasterWorld Admin, trillianjedi says;
Source ordered content
Pull the AdSense code last and position with appropriate CSS DIV markup. I'm not sure that's all easy in my particular case as I'm using a full float CSS layout already which is probably pushing the margins of what is currently possible. I don't know that it would stand any additional complexity.
This is the preferred method. Of course, adding some timeout code to the page, just in case Google goes down would also help with things.
Forum discussion for other solutions at WebmasterWorld.