TM Sender is a module that allows user to send text messages to other users' cell phones. This is a simple module, but can be powerful in conjunction with other modules.
For example, one can write a script to hook into the AntiDos module. When somone tries to DDOS attack your site it can text message you. Or better yet, you can make it so users have the option of recieving forum posts updated to their phones.
Currently, it only supports Sprint, T-mobile and AT&T. Nextel, Verizon and Cingular are on our to do list.
Download and test on your phone. :)