Smart meters are meters that monitor electricity usage and wirelessly transmit their data to the electricity company. They are a part of the “smart grid”, and allow for better electricity control and usage reporting.
Clayton Smith was able to reverse engineer the data signal from the Elster R2S meters which are used in the Ottawa area on the 902-928 MHz band. The Elster meters use frequency hopping channels, and Clayton was able to receive 6 out of the 25 channels in his area, which should be sufficient, as most of the data packets are repeated on different channels.
He has released his GNU Radio program which will work the the RTL-SDR. Currently, it is capable of displaying meter readings and hourly electricity usage to a terminal.