Hi Michael

The modules I am currently using with excellent results are called the Xbee Pro, I got mine from Digi at http://www.digi.com/products/wireles...-zb-module.jsp, their shipping is next day and only 8 bucks ! Now you do need some sort of pcb to plug these into as they have a non standard pin spacing of 2mm(won't fit in breadboard). That being said there are alot of interface boards to choose from. I use an great interface that of coure has the requied connectors for the xbee along with a pic 18f2520 running @ 40Mhz. Its an all in one pic/xcvr package, with built in ICSP or serial programming ports. I also use a serial DTE interface board made by the same company, which has built in v/reg, rs232 level shifter and DB9 connector, ready to plug into pc com port, they also have USB. I got mine here : http://microcontrollershop.com/produ...oducts_id=2370 .
And to answer your other question, the Zigbee protocol is here to stay, already being used in a ton of remote sensing and monitoring apps(power,gas and water metering) The IEEE developed the zigbee standard in '04 and revised it in '07, so it IS quite new.

John