Waspmote is an open source wireless sensor platform specially focused on the implementation of low consumption modes which allows the sensor nodes ("motes") to be completely autonomous, that is battery powered. Lifetime of Waspmote sensor nodes may go from 1 to 5 years depending on the duty cycle and the radio used.
Waspmote is based on a modular architecture. The idea is to integrate only the modules needed in each device optimizing costs. For this reason all the modules (radios, sensor boards, etc) plug in Waspmote through sockets.
You will need batteries to use Waspmote as an autonomous device.
Waspmote Quick Tutorial
Waspmote Technical Guides
Sensor Boards Technical Guides
50 Applications with Waspmote
FAQ: Waspmote Vs. Arduino