Local Storage.
I don’t really want to use it to download stuff and keep it, that’s not what I’m looking for. But a way to, for instance, aggressively cache a web pages so I could, for instance, download the text of “The Importance of Being Ernest” and read it while waiting in queues etc. I can’t do this currently and have to rely on a functional EDGE connection or emailing myself the files and reading them from my email.
Add that to my wishlist for later versions of iPhone OSX.