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.
Put your Ardweeny onto a prototyping shield, and add regular shields to it!
Sometimes it would be very nice to be able to add connectivity to your Arduino/Freeduino project. The Adafruit Ethernet shield kit lets you add network connectivity!
The Adafruit Motor/Stepper/Servo Shield gives you excellent flexibility in ways to create motion with your Freeduino SB or Arduino microcontroller!
This Adafruit GPS shield turns your Arduino into a GPS location datalogger! (GPS & SDCard not included)
The HV Rescue Shield 2 is a high voltage parallel mode fuse programmer for Atmel AVR microcontrollers.
The LoL Shield is a build-it-yourself kit that creates a charlieplexed LED matrix for the Arduino
The assembled PWM shield will fit on any board that is pin compatible with an Arduino and will give you control over 32 PWM channels instead of the standard 6 on the Arduino Uno.