Did you know that you can now send free text messages directly from Gmail?

Follow the steps below

1. Enter your contact’s name in the ‘Search or invite friends’ box in Chat, and select Send SMS from the box of options that appears to the right of your contact’s name. Or, if you already have a Chat window open for this contact, just click Options, and select Send SMS.
2. In the dialog box, enter a phone number in the ‘Send SMS messages to this number’ field. This feature is only launched in selected countries. To see the list of supported countries and operators, Click here. If you are not located in one of these countries you can still use it, but you won't see the SMS option in Chat until you enable it manually in the Chat settings page.
3. Click Save.
4. A Chat window appears. Just type your message as you would normally. When you hit Enter, the message will be sent to the phone number you entered.

Source: Web Tutorials

Good tutorial, but is it free to mobile network in Nigeria? Thanks for your reply.