Bruno hacked his Bus Pirate to be a ZigBee sniffer. He built a small protoboard adapter that connects the Microchip MRF24J40 module to the Bus Pirate IO header. He also wrote custom firmware that captures IEEE 802.15.4 traffic, and passes it on to a custom client app over USB. Check out his wiki page for further information and source code.
For those who want to connect a MRF24J40MA transceiver module to their Bus Pirate, I have put pictures of the small proto board adapter I use on the wiki page.
Thanks Bruno! Via the comments.
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