Great idea, down with captchas! Can you do this asynchronously? It does take a long time, but I only noticed because I clicked on something and waited for som

Great idea, down with captchas! Can you do this asynchronously? It does take a long time, but I only noticed because I clicked on something and waited for something to happen. If you start PoW on page load (perhaps save success result in localstorage) then probably even 30 seconds of processing isn't bad at all.