Somebody on Facebook recently asked about finding an easy-to-use shield helpful for experimenting with Arduino ... sensor, digital pin D2 is for the infrared receiver module, and digital pins D4, D7, ...

[Daniel] created an Arduino Sensor Shield to interface with Scratch, allowing for real-world input to the language. This board is a derivative of the Picoboard, which is designed for use with Scratch.

Because of the affordability and seeming ubiquity of the Arduino platform, they have been hard at work this last month trying to get their Geiger counter sensor board for an Arduino out the door.