Libelium Xbee Shield
Photo credits: unknown
Shield URL: Xbee Shield
The Xbee shield allows an Arduino board to communicate wirelessly using Zigbee. It is based on the Xbee module from MaxStream. The module can communicate up to 100 feet indoors or 300 feet outdoors (with line-of-sight). It can be used as a serial/usb replacement or you can put it into a command mode and configure it for a variety of broadcast and mesh networking options.
The shield breaks out each of the Xbee's pins to a through-hole solder pad. It also provides female pin headers for use of digital pins 2 to 7 and the analog inputs, which are covered by the shield (digital pins 8 to 13 are not obstructed by the shield, so you can use the headers on the board itself).
Open Source: Unknown
License Note: I can't find license information for this shield. It appears that even though the design files have been made publicly available there has been no license specified either in the design files themselves or on the site on which they are published. Unfortunately that means it's effectively closed source and the design files can't be used for any purpose unless specified otherwise by the copyright holder, Libelium.
The reset button on the XBee shield connects to the Arduino's reset line via the ICSP header. +5V and GND are also sourced from the ICSP header. The shield physically blocks the entire power / reset header but does not use it.