TXTMob was created as a tool political activists could use to organize their work, form staff meetings to street protests.
To sign up for TXTMob, users enter their cellphone numbers into the TXTMob Web site, www.txtmob .com.

To thwart spammers, the system uses opt-in registration: a machine-generated authorization code is sent to each registered number and must be re-entered into the Web site to activate the registration. TXTMob is designed to carefully maintain members' privacy, not surprising given why most are using TXTMob.

Of the 142 public groups listed on the TXTMob site, the largest are dedicated to protesting the Bush administration, the Republican Party or the state of the world in general.

...TXTMob had its first major New York workout on the evening of Aug. 27, during the Critical Mass, a loosely organized bicycle ride through Manhattan by anti-Republican protesters. From the start of the ride, participants in a TXTMob group called comms_dispatch sent a slew of messages alerting one another to route changes and warning of traffic snarls. As the ride neared its end, comms_dispatch buzzed with reports of arrests from Second Avenue to 10th Avenue, and around St. Mark's Church in-the-Bowery.