Hi folks, Probably the most impressive application I've run into for the iPhone has to be Facebook's implementation. I'm looking for ways to improve my application to be as responsive as theirs. Unfortunately it has quite a way to go. Does anyone know how this form of 'routing' works? For instance the home page for iphone.facebook.com looks something like: http://iphone.facebook.com/#home.php then if you click on profile it'll route you to something that looks like http://iphone.facebook.com/#profile.php?id=XXXX Is this actually 'leaving' the page and requesting profile.php? I'm completely confused with the hash mark in front of the PHP file and the mechanics behind this style. It seems to be extremely well implemented though and I'd like to learn more about it. I'm having a ton of issues with my application now where Ajax calls randomly do not get sent to the server. I haven't figured out why, maybe mobile safari is caching request URLs. But I'm looking to rebuild parts of the architecture to get it to work, and would love to understand the mechanism being used above. Does anyone know what is going on with the browser and HTTP requests with the methodology listed above? Any further reading? Thanks! - sf