A few days ago the Chaos Communications Congress (a technology and hacking focused conference) commenced. Amongst the talks there was one about reverse engineering the Iridium satellite paging system using software defined radio. Iridium satellites provide global communications via special satellite phones, pagers and other transceivers.
In the talk the speaker shows how they used a USRP radio together with a cheap active iridium antenna, a bandpass filter and an LNA to receive the Iridium satellite signals. They also mention that an E4000 RTL-SDR together with an LNA and appropriate home made antenna for frequencies in the ~1.6 GHz region can also be sufficient. Once they were able to receive signals they were then able to reverse engineer the signal and create several pieces of software to decode the pager messages. The code is available on their GitHub at https://github.com/muccc/iridium-toolkit.
The Ettus USRP B210 is an advanced $1,100 software defined radio that is capable of both transmit and receive. Balint, one of the researchers at Ettus, has posted a video showing how he was able to play a light hearted prank on some of his colleagues using the B210.