How often do you try to chat with somebody and they don't respond because they just walked away from their computer? Or maybe you're in the middle of chatting with them just as they need to leave. But you still need to tell them something -- something really important like you've moved where you're meeting...or ice cream! We need ice cream! This is why we built a way to chat with your friends even when they're away from their computers. Now you can keep the conversations going with a new Labs feature that lets you send SMS text messages right from Gmail. It combines the best parts of IM and texting: you chat from the comfort of your computer, and your friends can peck out replies on their little keyboards.

A few weeks back, we ran into a few snags when we first started rolling this out, but starting today you can turn on text messaging for chat. Just click on Settings, and go to the Labs tab. Scroll down until you see "Text Messaging (SMS) in Chat" and select Enable and Save Changes.

We're just trying it out for cell phones in the United States right now, but you can send texts to your friends with US phone numbers from anywhere in the world. You can start by just typing a phone number into the search box in the chat window on the left, then select "Send SMS." You can also select the contact you want to SMS first and then add their phone number.

Once you give us a name for that phone number, you'll be able to start chatting.

We'll save your friends' numbers in your Contacts, so next time you can just type their name in the chat box and select Send SMS.

On the receiving end, when you get a text message from Gmail on your phone, it will come from a number in the 406 area code. (The l33t folks in the crowd will note that this spells G0O.) You can reply to this text on your phone just like you'd reply to any other text. The reply gets routed back to our Gmail servers and shows up in your friend's Gmail chat window. Each of your friends' messages will come from a different 406 number so you can reply to any message and it will get back to the right person. Messages from the same person will always come from the same number, so you can even bookmark it in your phone.

If you get a message from somebody you don't want to chat with from your phone, just reply with the word BLOCK. If you don't want to get texts from anybody using Gmail, reply with the word STOP and we'll leave you alone. Keep in mind that all these text messages count as part of your regular mobile messaging plan and might incur fees. So unless you know your friends have unlimited text message plans, please be sensitive to their phone bills.