I need 60 analog input pins .... how

That is
I need 60 analog input pins.
I need to follow a shadow so I thought in a line of light sensors
the line can be covered with about 60 sensors. Knowing the sensors position I will know
where the shadow is ....

how can I connect about 60 light sensors to an arduino board ?
any idea of a better way to do that ?


Use analogue multiplexer chips.

Yep, you can get 16-port multiplexers, so 4 of those, connected to 4 of the Arduino analog inputs, should do it.

Bear in mind you still have the overhead of reading each one (around 104 ┬ÁS each).

If you need to follow a shadow, is it moving on consecutive points / sensors, or is it jumping all over the place ?
If it follows a fixed path, you don't need to read all sensors every time, you just need to know whether it moves forward or backward (or not at all).
That can save you a lot of time.
Also read a sensor of which you know it is not in your shadow.
Use that value for calibration, to compensate changes in the lighting because you depend on that.

There is a another trick.

You use two multiplexers, 74HC4051. One is used to ground the "rows" of your 8 by 8 matrix of sensors, while the other connects a given matrix "column" to the ADC input (which has a pull-up to Vcc). If the sensors are naturally diodes, such as photo-transistors, you simply have the emitters to rows and collectors to columns. If they are bidirectional, such as LDRs, you have a diode in series with each, cathode to "row", anode through LDR to "column".

Of course, another way to do this is to have one LDR or photo-transistor at the end of a black tube, mounted on a servo arm which you use to "scan" for the shadow.

Good idea. That would be less wires, too.