if You searching method of sending free SMS from internet you are at right place
we have a trick from which you can able to send message from your Facebook account
by simply going on this facebook aap  http://apps.facebook.com/chatsms/

Instuctions :
Step 1 : open www.facebook.com
Step 2 : Login with your username and password
Step 3 : Open this url: http://apps.facebook.com/chatsms/
Step 4 : Allow and grant permission to access your profile data
Step 5 : you will see this page

Step 6 : Just select your country, write your friends phone no whom you want to send sms
Step 7 : click on send sms button
Step 8 : some time it show error, but do not worry your friend will get message which you have send within some minutes.