travelin_cat - 4:03 pm on Dec 31, 2009 (gmt 0) From Google:
Page Speed in WMT is based upon the load time of visitors to your site. So it takes in to consideration people with slow connections as well as very fast connections.
Page load time is the total time from the moment the user clicks on a link to your page until the time the entire page is loaded and displayed in a browser. It is collected directly from users who have installed the Google Toolbar and have enabled the optional PageRank feature.