You asked for SMS, and I'll give you the SMS answer, and then explain why those that gave you non SMS answers have better solutions. If you were on say, TMobile you could use something like SMS::Send::US::TMobile and there are some other phone carriers under the Net::SMS branch.

Having said that, MOST carriers do not have public SMS gateways. They have private ones for pay. Why is that? Mostly we have the spammers to thank. When SMS gateways were public, phone customers started receiving 'stock tips' and what not. That's annoying enough, but getting charged for it was too much. Once the phone carriers started getting a deluge of phone calls they decided that public SMS gateways were the problem and just shut them down. SMS, by default, has less traceability than say email. This is why SMTP gateways are still public and that's why so many people use them to get to their phone. If your phone has email support, I'd recommend going that route.