The SMS Fu plugin lets you send SMS text messages – for free – by letting your users enter a cell phone number and a carrier. The plugin avoids incurring SMS charges by using the carriers Email-to-SMS gateways.
You can also find out more at the SMS Fu homepage.
Author: Brendan G. Lim
Installation:
ruby script/plugin install script/plugin install git://github.com/brendanlim/sms-fu.git