title: Polling, Comet, WebSockets, etc
body: <p>I'm needing to build in some pretty agressive "auto refresh" capabilities into a web application. It's kind of a photo gallery and the images are stored on AmazonS3 but the data about the images are stored in our own database. I've played around with polling the server and sending ajax calls to get the updated data. I'm really concerned about the load on the server(s) with this method. At times, the page would need to be updated every 15 to 30 seconds.</p>
  
  <p>I've been reading on Comet and I'm just not sold that this "hack" is a great idea. WebSockets would probably help but I'm concerned they are just too new and too unsupported. So, that being said, does anyone have any recommendations on ways to architect a system that needs to refresh that often and has the potential for a very high user base? </p>
  
  <p>I'm not apposed to just throwing more servers at the problem but not convinced that is the best approach either. And before anyone else suggests it, I can't do Flex, because the web app has to function on the iPad.</p>