This article on DevelopersHome.com claims to tell you how to directly interface to the phone and use old-school modem commands like AT. You can write an application for this, but you'll have to learn some fairly advanced programming techniques, and decipher the SMS packet standards. Something that is not readily available for obvious reasons. Your application also won't be portable to HTTP SMS when you're ready, so prepare to cough up some more money.

Next option is to use HTTP SMS gateways, the most common method. This does require an internet connection, but eliminates most of the limitations inherent to other methods. This is accomplished by establishing an SMSC account with some wireless server, with prices typically ranging from $.05-$.08 per message depending on volume. This method is completely scalable though.

You can interface with these gateways programmatically using HTTP and SOAP, meaning a solution can be designed using something like ColdFusion or PHP connected to a relational database. Again, all you get are the APIs and service account for your money though. Still, if you're a programmer you'll be buying 10000 messages for $550 instead of some unproven software.

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There is another possible technique, but it would still require internet access, whether through your phone or the standard way. Most wireless phones can receive text messages via standard email. You just have to know the phone number and the naming convention of the service provider. For instance, T-Mobile receives at *phonenumber*@tmomail.com, and Verizon at *phonenumber*@vtext.com

Mark my words, that will go away very soon though. Providers know how the demand for text messaging has increased, and they're not going to continue to let a piece of the pie slip through.