Possible to use photoresistors as digital in?

I'm working on an musical instrument project using photoresistors as a triggers. Right now I have them going into the board's analog ins, set to trigger when they reach a certain threshold. I'd like to have more than six of these photoresistor triggers (8 - 12 is ideal) and use the analog ins for some different inputs (potentiometer to adjust pitch, etc).

So: is it possible to use photoresistors as digital inputs? And if not, are there others light-sensitive sensors that I might be able to use in this way?

You can use a digital input. The switching might not be clean since there is a undefined state between 0V and 5V where the input isn't guaranteed to be 0 and isn't guaranteed to be 1. As your variable resistor changes and the voltage passws through that region you may get random switching. I think you can use a Schmidt Trigger inverter to clean up the input. It provides solid switching on a slowly changing signal. Each 74HC14 chip will do 6 channels.

You could use a LM 339 quad comparator to condition the signal from the photo resistors and also set a threshold for the switching. By varying the reference voltage at the comparator you can adjust the voltage level (light strength) that switching takes place. A Schmitt trigger will have a fixed trip point.

Yes it is, but you'll need to connect the photoresistor in series with a plain resistor and the value of the plain resistor must be chosen so that the digital input switches between a HIGH and LOW state at the brightness you want it to. You might find it convenient to use a potentiometer here so that you can adjust the value. You would connect the digital input to the junction between the photoresistor and the plain resistor, and the free ends to 5V and ground.

Have thought of multiplexing the analog values with an analog switch ?