Twitter (for now) has a very simple sharing intent. There is no need to include a massive script into your sites to offer a "share this" button.
For example, click the following link:
Tell Twitter about this
Enter your information (leave empty what you don't want)
This simple script can help you dynamically alter a share button. See the source of this page as an example.
1) Make sure you have a link in your HTML, like this:
<a target="_blank" id="myshare" href="https://twitter.com/intent/tweet"> Share Beedogs </a>
2) Include sharebutton.js
3) Set the configuration
sharebutton.config.hashtags = 'dogs,beecostumes'; sharebutton.config.link = 'http://beedogs.com'; sharebutton.config.account = 'codepo8';
4) Give the script the DOM selector and the text to set
sharebutton.set( '#twittershare', 'Best dogs in bee costumes site on the web' );
You can of course keep the config, and simply re-set the text or have it as a result of a concatenation.