Bottom line: I've never found anything cool, easy and integrated for Twitter. Well, until I met theTwitter Gadget for Gmail, an application developed by the user @ c9 that takes advantage of Google App Engine. Another very interesting point is its Ajax functionality and a very similar interface to Gmail, which makes the gadget perfectly integrated. (Yes, it automatically updates to keep up with new Tweets!)
To install the gadget inside Gmail very simple, just follow the instructions below:
1. Inside Gmail Labs (only available for Gmail in English), enable experimental functionality ?Add any gadget by URL" 2. In the Gadgets tab within the Gmail settings page add the URL: http: //twittergadget.appspot/gadget-gmail.xml and click on ADD. 3 A new box called "Twitter" appears in the left sidebar of Gmail. 4 Click on the respective option to allow access to your Twitter account. 5 Authorize access to your Twitter account by clicking the "Allow" option. 6 Back in Gmail, click the second link to reload the app. At this point the gadget should recognize the authorization and start working (if not, do process 4 and 5 again). 7 By clicking on the "Twitter" link at the top of the gadget on the left sidebar, you will be able to see the maximized Twitter on your screen. You can tweet, reply, tweet, read your replys, direct messages, and more.
Any questions, leave a comment on this post that we will try to help you!