This isn't going to be a world-changing extension for anyone probably, but I created an extension that easily puts a twitter button into your QVW. It also allows you to set a hashtag and link value that is added to the tweet automatically.
It's very easy to set up. Here are the properties:
These properties (obviously) control the hashtag and link values that will be automatically added to the tweet of the person who clicks the button.
When a twitter user clicks the button, a window will show up like this one which has the link and hash already in it:
Pretty simple. Let me know if you have any problems with it. I've also attached a technical brief of the extension which goes into some detail on the code.