Select Link is a jquery plugin that provides a pop
up when words on your website are selected.

The plugin can be found here.

This plugin can be used in many ways. Some examples :

• Allow people to search for a word on your website
  with a Search Engine or within your website.
• Tweet a word or a phrase directly.
• Search Twitter for a word or phrase.
• Search an API, for instance the Drupal API for any
  function on your page by simple selecting the word.

Check the documentation
for a list of configurations and how you can use it.