SMS messages are a very popular form of communication today. Literally billions are sent out around the world every day, many of those by cell phone users. Sometimes it is more convenient to send text messages from your computer, especially if you are at work. You will need to register with a site that provides the software to do this, but as of 2010, many of these sites are free to use.
Go to a website that offers free text messaging service such as 411 SMS, Chikka or TextEm.
Register your mobile number on the site that you choose. You will also need to provide a user name, password and e-mail address. After you've completed the registration process, you will receive an e-mail. Click on the link in the email to confirm your registration and log in to the website.
Compose your text message. You are limited to 160 characters. Once you have composed your message, type the recipient's cell phone number into the appropriate field.
Enter the verification code and click "Send." The service will automatically send the message to your recipient. When the recipient replies to the text message, a notification will appear in a popup window on your desktop. Click on it to read the message.