I believe the vBulletin default rate on the refresh is 1 minute. About a year ago you changed the setting here to every 20 seconds, Which I thought was about right (even every 30 seconds is more than plenty). But I'm finding the 10 second refresh rate rather distracting, and so I'm not leaving my browser on the 'who's online' page any more except for a quick look.
Butch, Google does not direct me to any particular answer when I click your link. And the first result isn't even in English. But like Frans said, there's lots of general discussion about the adsense spiders although nothing directly from Google.
Oh, the suggested correct spelling? The first result from that search is fairly informative, but still just a forum discussion. Perhaps you might have just posted a direct link instead of a link to a link to a link. You made it sound like Google had a direct information page.