How to Send an SMS From GTalk

1. Navigate to Gmail.com and log in to your account.
2. Send an SMS to a contact by hovering your mouse over the person's name in your Google Talk contact list at the left and clicking 'More,' then 'Send SMS.' If the contact's phone number is stored in your address book, a new chat window will open and you can type and send the message from this window. If the contact's phone number is not stored in your address book, you'll be prompted to enter a phone number before the chat window appears.
3. Send an SMS to any mobile phone number by typing the area code and phone number in the search box at the top of the Google Talk contact list and then clicking 'Send SMS.' Type your message in the chat window that appears and press 'Enter' to send the message.