AnswerTips
AnswerTips from Answers.com are small information bubbles that magically appear when users double-click on any word on your blog. They provide fast and easy explanations, definitions and background information while reading, browsing or just surfing the web.
When your blog is AnswerTips-enabled, it gives users the power to get instant answers to their questions without ever leaving the page. By gaining access to 4+ million topics from best of breed sources in every subject-area imaginable, users have more content to enjoy, leading to longer visits and a more integrated user experience.
Give it a try and you’ll see what we mean!
Example:
Note that when you install AnswerTips, this rotating image will appear in your blog's sidebar to let readers know that the feature is enabled.