NOTE:As of 6/25/2008 it appears that this api is no longer available.
From their site: We help software developers provide their content on cell phones using 411sync's SMS (text message) API and standard technologies such as XML and RSS. Developers can use 411sync SMS (Text Message) Services to offer custom information to the users. Users request information by sending a text message (SMS) to a custom unique sms id created by the developer. In response, the custom information is sent to the user on the cell phone as a text message. All you need to do is send us data in web standard RSS XML format.
Many APIs eventually find their way to the ProgrammableWeb deadpool. They end up there for various reasons: no business model, replaced by a newer service or ceased being useful. The most popular of these dead APIs are predominantly from two big tech firms: Google and Yahoo. Search and mapping make up the bulk of the functionality behind these 12 popular--but no longer available--APIs.
2FA link from AMEEX mobile offers two-factor authentication (2FA) for users to secure accounts and prevent phishing attacks. The company offers a SMS API to send authentication request codes to users...