http://www.synapse-wireless.com/index.php?mainID=3&subID=3&type=product&prodID=3
Synapse Wireless makes "RF Engines" that run python. I consider them a smart XBee. They have two UARTs on them. The RF200 (soon to be released) uses an ATMega128RFA1 as the CPU. I have only worked with the RF100 series. The advantage over an XBee is that you don't need an arduino at every wireless location.
The RF Engines run python code that reads the sensors, filter the data, transmit is needed. They are very flexible.