!!! This no longer works and has been superseded by an official blogger plugin here: http://www.bloggerplugins.org/2010/08/twitter-share-buttons-for-blogger-tweet.html !!!
This article will take you through how to add Tweet Me button to Blogger and track.
Firstly you need a Blogger blog on which you want to add the Tweet Me button. Then you need the following code;
<b:if cond='data:blog.pageType == "item"'><span style='float: left; background: url(http://lh6.ggpht.com/_xn2gmPb9TfM/Sb_fZkjAxpI/AAAAAAAAD3E/_9xpsQgFfTg/s128/twitter-16x16.png) left no-repeat; padding-left: 20px;'><script charset='utf-8' src='http://bit.ly/javascript-api.js?version=latest&login=tweettrackjs&apiKey=R_7e9987b2fd13d7e4e881f9cbb168f523' type='text/javascript'/>
<script charset='utf-8' src='http://s.bit.ly/TweetAndTrack.js?v=1.01' type='text/javascript'/>
<a expr:onclick='"return TweetAndTrack.open(this, \"" + data:post.url + "\");"' href='#'>
<span style='display:none;'>I'm reading: <data:post.title/></span>Tweet this!</a></span></b:if>
Add this after the <div class=&'post-footer-line post-footer-line-1'> section in the HTML (remember to back up before changing and tick the icon to expand the widget templates). You may wish to take out the "float: left" to get the button formatting correctly with the rest of the text on your post. Now the text in red needs to be replaced. See the article here http://www.bloggerbuster.com/2009/03/how-to-add-tweet-this-links-to-your.html for detailed instructions on how to do this.
Now you need to create a bit.ly account at http://bit.ly create a username. The username you create should replace the tweettrackjs text highlighted in red above. Then go to Tools and scroll down to "Access Link Data Generated Outside of bit.ly" and then click "your api key" or click here http://bit.ly/account/your_api_key/ then copy your api key and paste above and replace the api key e.g. R_7e9987b2fd13d7e4e881f9cbb168f523.
Now when people tweet your link, or people click on the tweeted links the data will appear on your dashboard here http://bit.ly or http://**username**.bit.ly