It only sort of works on iOS 5, the downloads stop whenever a "Increase Storage" prompt pops up and you have to reload whenever that happens. But it does work with the small dump, albeit slowly.
Cool, I initially didn't think this much storage was possible on mobile yet. Are you saying you can get the whole thing down if you keep agreeing to the prompts?
It's a pity mobile browsers haven't got better support for this kind of thing yet.
No I think it stops issuing prompts after 50GB. Also, on iOS 5, it only supports WebSQL which dosn't store (AFAIK) objects like typed arrays, so I have to convert it to a string and back base64 encoded, which makes it use even more space.