That was my first though, and second one was there should be a centralized place for all the warrant canaries with a simple OK/vanished toggle. I have literally never checked the status of a canary.
Delivery drones (http://www.amazon.com/b?node=8037720011) could make amazon better than actually going out to buy even 1 roll of tape, and returning stuff too.
It does one thing better than a password manager: it prevents rainbow attacks via forced localized salting. That's about it... Next HTTP can solve other problems...