Replicate the Y2K scare on a smaller scale with Timer click.
Timer click is an elapsed time controller that lets you set an one-time programmable alarm that can go off after your device has been in use for a certain amount of time (anywhere from a quarter of a second to 34 years). You can use the alarm to make your device self-destruct. Less dramatic applications are also possible.
The board carries Maxim's DS1682 IC. It's a simple chip with only 8 pins. The two most important ones are EVENT and ALARM pins. Whenever the EVENT pin is held high, the clock inside the DS1682 starts ticking. When the pin is set to logic low, the timer will stop ticking and write the elapsed duration in the chip's internal EEPROM.
When the EVENT pin is pulled high again, the timer picks off where it left off and continues ticking. The internal EEPROM is a workaround that enables the chip to keep track of total elapsed time without a need for a backup power supply.
These kinds of chips are used for warranty tracking. Integrate it into any device and it's like a black box that records the total amount of time a device has been in use. The fact that the alarm can be programmed only once ensures that there is no tampering.