Scosche already have a portable RDTX detector which has the ability to send radiation warnings through your iPhone, but they've stepped it up a little here with the HRDTX. The HRDTX is designed to monitor your home, providing audible warnings and e-mail alerts when radiation levels become too dangerous.
The HRDTX uses "fast photo sensor technology" accurately measures gamma radiation without the need for calibration, and provides both visual and audible warnings depending on the "threat level". Green lights are always good, which means its safe, a yellow light with a beep every 30 minutes means that radiation levels are elevated. When the radiation levels become too dangerous, the HRDTX has a 105db alarm that will go nuts before the units light turns red.
It even features Wi-Fi, which allows it to send an e-mail to the homeowner while they're away from the house reporting to them that the radiation levels have risen to the point where it is no longer advisable to return.
Scosche's HRDTX sells for US$330.