Now here’s something which will interest you. You can send Free SMS from Gmail i.e from Google Talk in Gmail.

Visit the Gmail Labs Page, to activate this new feature and scroll down until you see the appropriate listing.

To send a message, just type a phone number into the search box at the top of the chat window on the left side of the Gmail interface, and hit ‘Send SMS’. Numbers can be associated with contact names so you don’t have to keep manually entering them. Recipients of these messages can respond by simply hitting ‘reply’ on their cell phones to send their own SMS message (Gmail ties a unique phone number with each of your contacts)

Now this new feature is currently tested only with U.S phones.