Meet the Simtek Wireless Security Sensor: a smart gadget that lets you keep an eye on your drawers and weapons in general. The device uses its own cellular connection to send you alerts over an encrypted connection. It can detect light and motion (with a range of 15 x 15″) to let you know if there is activity around your valuable items.
Multiple users can be added to the same time. The sensor lasts up to a year on battery.[where to get it]