One approach would be to send a text message with your gmail account
using System.Net;
using System.Net.Mail;
public void SendTextMessage(string subject, string message, long telephoneNumer)
{
const string sender = "me@gmail.com";
const string password = "mypassword4gmailacct";
string carrierGateway = "txt.att.net";
string recipent = string.Concat(new object[]{
telephoneNumer,
'@',
carrierGateway
});
using (MailMessage textMessage = new MailMessage(sender, recipent, subject, message))
{
using (SmtpClient textMessageClient = new SmtpClient("smtp.gmail.com", 587))
{
textMessageClient.UseDefaultCredentials = false;
textMessageClient.EnableSsl = true;
textMessageClient.Credentials = new NetworkCredential(sender, password);
textMessageClient.Send(textMessage);
}
}
}
For a List of Sms Gateways check
http://en.wikipedia.org/wiki/List_of_SMS_gateways[
^]
Note: When the recipent responds to the message the message will be sent to your gmail account...Great for backups :-)