The LEVITICUS handset is a hand held GSM frequency analyzer and GSM sniffer. It is disguised as a common Motorola phone, mostly because it is a common Motorola phone with some custom firmware. Compare to the GENESIS handset from the ANT catalog.
Motorola C139 Cell phone (avoid Tracphones, but Cingular branded phones work great)
OsmocomBB cable http://bb.osmocom.org/trac/wiki/Hardware/SerialCable
Boot TWILIGHTVEGETABLE environment.
For frequency scanner, run ./rssi.sh
For GSM sniffing, run ./layer1.sh to load the layer1 firmware, and ./ccch_scan.sh to dump GSM packets