Chakri's: SMS in gmail

appear in the sender’s desktop Gmail interface. The message can be stored and archived like any other chat or IM messages.

In order to use this feature you have to enable the SMS (text messaging) in Chat lab. You can send Free SMS messages to your contacts’ mobile phones using Gmail Chat. Here’s how to Send Free SMS from Gmail:

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.
In the dialog box, enter a phone number in the ‘Send SMS messages to this number’ field. For now, this feature works only on United States phone numbers. If you’re outside the US, 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.
Click Save.
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.

If your contact replies, the text message response will appear as a reply in Chat. These conversations are stored in your Chat history just like regular chats (but keep in mind that you can’t go off the record while communicating via SMS).

When replying with an SMS from phone to Gmail, you will be charged a regular SMS rate by your mobile provider. However, sending SMS from the Gmail Chat to a phone is FREE. As of this moment, every user can initially send up to 50 messages continuously. Every reply back from a mobile phone refreshes the counter by five messages, up to a maximum of 50. Even if you go down to zero, however, you will not be locked out of the system. The counter will increase back up to one 24 hours later.

SMS credit in Chat

SMS credit is an allocation of SMS (text messages) that you're able to send to a mobile phone:

Initially, you're granted a credit of fifty messages.
Every time you send a message, your credit decreases by one.
Every time you receive an SMS message in Chat (for example when a phone user replies to one of your messages) your credit increases by five, up to a maximum of 50.

If your SMS credit goes down to zero at any point, it will increase back up to one 24 hours later. So, you won't ever be locked out of the system.

"Buying" additional messages

Keep in mind that if you'd like a higher message credit, you can always send an SMS to your own phone, and then reply to that message multiple times. Every time you send a reply message, your SMS credit is increased by five. Effectively, you're buying more messages by paying your phone company for these outgoing messages. More about Gmail SMS chat: