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.
The new 3G/GPRS module for Waspmote allows sensor networks and M2M devices to connect to the Cloud by using high speed WCDMA cellular networks in the same way as Smartphones do. This makes possible sensor nodes send not only discrete sensor information such as temperature or humidity (which can be encoded using just a single number) but also complex streams of information such as photos and videos. This new feature allows developers the creation of new Smart Security applications.
You will need batteries to use Waspmote as an autonomous device.
Documentation:
Waspmote Quick Tutorial
Waspmote Site 
Waspmote Technical Guides 
Sensor Boards Technical Guides 
Networking Guides 
Developers Forum 
Videos 
Articles 
50 Applications with Waspmote 
FAQ: Waspmote Vs. Arduino