I'm asking a question on behalf of my brother who runs a youth non-profit org in Providence, RI.  He's looking for a way to send text messages, en masse, to an opt-in network of constituents (mostly teens).<p>Can any recommend any good services to handle that?<p>He's looked at the follow:<p>http://www.sumotext.com/<p>http://www.eztexting.com/<p>http://www.txtmobster.com/<p>He's also looked into working with carriers directly.  I really don't know what is the best way to handle an opt-in, group text alert list, or if any of these companies are reputable, so I thought I'd ask the HN community.<p>Thanks!
Ask HN: Mass SMS text message services?