Internet access using regular consumer devices (routers, smartphones, tablets, PCs etc) in P2P fashion. Using whatever physical tech available (primarily Bluetooth & Wi-Fi, but anything goes).<p>Think https-over-BitTorrent + mesh networking<p>This could do away with (some of) the centralized internet topology we have today.
Calculating the last digit of pi. That, or an alarm clock that recognizes when I press the "off" button instead of "snooze" while being still a zombie, and corrects it automatically. (But it should also recognize it when I press off intentionally)
Have AI automatically create described audio for old tv shows that apparently will never get a corporation to go back and add a described audio track even though there streaming.