Now you can Tweet from GTalk too

1. First start G Talk and Login

2. Then Go To Tweet.Im . To sign up, you just need a Twitter account and a Google Talk account

3. Once you register on Tweet.im you would see that there is a Friend request from YourTwitterName@twitter.tweet.im .

4. Accept that Tweet invitation. Now whenever you want to tweet just use it to tweet just like you chat with your friend.