You might want this one instead of the one with UF.L connector, which requires an
external dipole antenna.https://www.sparkfun.com/products/10822
And yes, it plugs into the standard XBee shield, and makes comms via RS232. There is one
problem people always make, which is trying to connect the XBee module [or RN-XV] Rx,Tx
to the Arduino Rx,Tx pins at the same time as connecting to the USB port of the PC.
Naw-uh, the signals conflict. It's either one or the other, or else connect the XBee Rx,Tx to
pins other than 0,1 on the header. Alternatively, it is possible to connect the XBee to pins
0,1 after disconnecting the bd from the PC, but then you don't have simultaneous debugging.
This is always a problem with the mega328 Arduino bds.