tedster - 5:59 pm on Apr 22, 2008 (gmt 0)

If we check the datacenters using IPs in the URL, the browser shouldn't send the login cookies to google. So I think this should work as well.

That's what I always thought, too - but dudibob reports seeing different results. I can't easily test this because I intentionally avoid doing searches while logged in.

There is one other possible explanation - Matt Cutts explained that even the same IP does not always point to the same data center.