MacRumors had a PHP page that gave up to the minute details on Steve Job''s keynote at MacWorld by using AJAX to refresh the page at regular intervals (thus keeping users from constantly reloading the page). They have posted details about their system as well as some interesting stats. http://www.macrumors.com/events/mwsf2006-stats.php To summarize, they served 32GB of data in a three hour period. They estimate that they would have served 196GB of data if they hadn''t used AJAX. That''s a reduction of 84%. Even though it''s PHP and not Rails, I thought the list might find it interesting. It might also help someone sell a client on the benefits of adding in certain features to a project. Kevin Skoglund