An inifinitely Long Web Page

Way back in the good old maya days, Jon West and I talked about a web page that grows as the user scrolls down so that the page is essentially endlessly long. Today, I found that the Google Reader does this exact thing. Scroll to the bottom and it loads more content and you are no longer at the bottom. I wonder if this was a point of humor for the Google developers. It's a bit like a tease game where someone ties a string to a purse and when someone tries to pick up the purse, they pull the purse. Can't quite get there from here.