I just wanted to get this out there, Android’s browser caches like a madman. It completely ignores POST variables. This is particularly relevant when doing AJAX calls. You can’t simply add a timestamp to POST and expect the Android browser to give you new page data. You have to append to timestamp to the GET query string.
Pragma: no-cache, and all the other server-side headers also have no effect as far as I can tell.
It makes sense though. Since the browser’s on a mobile network, and since they want to minimize network traffic as much as possible, caching is going to be extremely aggressive.