Some members of the amateur radio community enjoy various challenges, and one of these is the "fox hunt". This involves hiding a low-powered transmitter somewhere remote, which broadcasts a CW signal or message in Morse Code. Then the participants use their knowldge of radio to device antennas and locate the "fox".
An example of a transmitter with an Arduino has been described by Dr. Carol F. Milazzo, KP4MD who uses a surplus modified sonobouy as a transmitter of a signal in morse generated by an Arduino-compatible board. This provides an inexpensive and robust target for the aims of any foxhunt. A quick demonstration of the ouput can be heard in the following video:
For a detailed analysis of the project and some other interesting reading, visit Dr Milazzo's website. And for more, we're on facebook, Google+, and twitter - so follow us for news and product updates as well.