The XBee Explorer Regulated takes care of the 3.3V regulation, signal conditioning, and basic activity indicators (Power, RSSI and DIN/DOUT activity LEDs). This makes it SO much easier to start playing with XBee!
It is the most easy and reliable way to connect the Xbee module to a PC via USB port.
The Synapse SNAPstick is designed to be a compact and easy way to connect a PC to a SNAP wireless network via your PC USB port.
Want to add ZigBee communications to your MAKE Controller? Here's the interface board you'll need!
This proto shield comes with a socket for wireless modules, such as the Digi XBee, and a built in regulator and a big ol' prototyping area.