Techreceipes posted an article today on how to use Gtalk as a Twitter client. Its pretty easy to setup Gtalk to start twittering...here is how :
1. Go to Twitter and login to your account.
2. On the home page, go to the side bar and click the Activate your IM! link.
3. Under Instant Messenger, input your Google Talk username. Make sure that GTalk is selected from the dropdown. Click the Save button.
4. Clicking the link to verify your account didn't work for me. Leave this page open because it contains the series of letters that you will need to send to firstname.lastname@example.org to verify the account.
5. Open Google Talk.
6. Click the Add button at the bottom of the Google Talk client to create a new contact.
7. Input email@example.com into the textbox. Click Next.
8. Click Finish.
9. Open a chat session with [i]firstname.lastname@example.org[/b].
10. For your initial message, input the series of letters that are in the Twitter page that you left open. Submit the message.
You are now ready to Twitter from Google Talk.