It's easy to send SMS's from your own website. Follow steps 1 - 4 below:
First you need to add some credit to your account. Click on the "Credit" Folder.
Note: You will be taken to the PayPal Secure Payments Website.
Click on the "Account" Folder, "Generate New Key" and then "Update".
Copy and Paste the code below on your website.
// (1) Create SMS Object
o_obj = new ObjTmmAPI();
// (2) Set User Id and Key
// (3) Set SMS App Id
// (4) Set Country Code, Phone No and Message
o_obj.Sms('61','0412345678','This is the SMS Message');
// (5) Finally, Send the SMS!
If the SMS is successfully sent an entry will appear in your SMS's Folder.
SMS API Cost: $0.12c (USD) per sms
That's it, you can now send SMS's from your website.