Google now allow you to send SMS from your gmail. You simply type in the 10 digit number, area code and phone number, in the chat window. It then offers you to send as an SMS. Type in the message and click send.
It turns out that they have disable it because of some bugs. It shall be up and running in around two weeks again.
Here is what google said,
“When you’d try to turn it on, it wouldn’t fully enable. We thought about keeping it out there — bugs and all — but the experience wasn’t that great. So, in the spirit of Labs, we’ve pulled SMS chat back to fix it, and we’ll get it back out to you as soon as it’s ready — probably within 2 weeks, so stay tuned.”
Via Google Watch