Of course, we’ve seen GSM and cell phone shields for Arduino before. Difficult to imagine sticking those in a dog collar, though, unless you have a fairly large dog. If you are a fan of 1960’s ...

but this is the first one we’ve seen that turns your Arduino into a proper cell phone. The shield is based around the SIM900 GSM/GPRS radio module, and is compatible with the SIM908 GSM/GPRS ...