I Love the smart phone app id ....
I think the odds of guessing the next random number from a smart phone is going to be rough ...
why can't I have a app that app on my smart phone app that sends a random number to mt gox or tradehill (only good for 3 mins) that I have to enter in to the site to login
Not sure how that would solve a database hack (like at gox) but would require someone to break the password and have the verified cell phone (over sms, an android app could watch for it in setting up the phone the first time)
It would allow me to not have to buy some key, and what happens when I lose/break the key ?