Verified answer

Did you want to incorporate the light sensor as well or just use a switch? Both are fairly simple and require just a bit of soldering.

If you want to use both the photosensor and a switch, first identify the photosensor and solder a switch in series with it, either before or after the sensor. Solder it before the sensor if you want the switch to activate the sensor. Or you can solder it after if you just want the switch to work when it is just the right lighting condition.

If you simply wanted it to work with a switch then it is a simple component replacement. You are going to need to desolder the sensor and just use a drop in replacement switch. I am looking at the cricket kit now and since it would be difficult to mount a switch on the board itself, I would just solder some wires to the existing sensor terminals and add a switch like this

http://www.radioshack.com/product/index.jsp?produc...

You can use a spst switch too but I like spdt (Single Pole Single Throw vesus Single Pole Double Throw). The throw is referencing how many positions the switch can be in, like a button versus a common house switch in any residential home.

Put a switch in series with the LDR. When the switch is in the off position the circuit will think it's dark all the time and so operate.