Free SMS API
You can use all 160 characters with any advertisements attached.Free SMS API is available in different programming languages like PHP, Java, Perl, Python, Ruby, C, VB.NET and C# to integrate with your website or product.
Send SMS by uploading your contacts using CSV or XLS file.
Sender ID is Free on promotion basis and is valid for 30 days after activation, After 30 days a small free would be applicable.
More information: http://www.freesmsapi.com/company/features