Twitter just announced a new addition that will add new punch to the web developer's social networking world. It's called the "tweet" button.
The tweet button is extremely simple to implement, and the fact that it will be supported by Twitter is a great advantage. Keeping the functionality of the tweet button performing properly will be in Twitter's best interest, and this should lessen the likelihood of the button failing.
When added to a website, the tweet button will automatically create a shortened url of the page on which it is located. It will also add a link to the Twitter account of the originating website (@Element_31) when explicitly set to do so.
A company called TweetMeme had already developed a "retweet" button that is widely used today before Twitter brought forth its own "official" implementation. TweetMeme is reportedly working with Twitter to assist with improving the tweet button, and they are also continuing to develop new Twitter-related applications, themselves.
More details on how to use the tweet button can be found on the Twitter goodies page. Web developers can find even more detail and customization notes on Twitter's developer page.