lucy24 - 5:14 am on Oct 18, 2011 (gmt 0)

... but note that this won't do you a particle of good if the user's ISP does their own remote caching. Once they've decided that a given page is current enough, no power on earth can make them reload before they are good and ready. A local provider recently got some bad press (which they completely ignored) thanks to caching anything and everything-- including things like registrations for popular social sites with the most recent visitor's information all nicely filled in.