You can still use them as "digital" inputs for reading buttons & switches for example. I doubt you can use digitalRead() with those pins, but you can certainly use analogRead() and compare the reading with a threshold like 512. There are no internal pull-up resistors on those pins either, so you will need to add external pull-up/down resistor.
You can, of course, use them to read multiple buttons & switches connected to the same pin using combinations of resistors to give each button/switch a unique value.