Students Ido Livneh and Gil Freidlin from Tel Aviv University have been experimenting with garage door opener signals using the TI Chronos watch and RTL-SDR dongle. Their technique involves using the SDR along with HDSDR software to acquire and record the signal, which is then analyzed using Python based tools and encoded for loading onto the Chronos RF wristwatch.
The project report is available as a 23 page PDF download.
Via RTL-SDR.com.