Although text messaging is most commonly considered a cell phone to cell phone medium for communication, it is possible to send multiple text messages directly from your PC to a phone using intermediary websites which convert the messages to the appropriate format, depending on the cell phone carrier, and broadcast them externally to the appropriate number.
Navigate your browser to the TestEm.net site (see Resources below).
Enter the number of the recipient's phone in the boxes provided.
Select the phone's carrier from the drop-down list.
Input your message in the text box.
Enter the displayed security code into the available box.
Press the "Send Message" button.
Repeat the above Steps to send multiple text messages.
There are many websites that provide free computer-to-cell phone texting services.