Search the web or look up words by clicking on them and view results inline without leaving the page.
This extension allows you to perform searches or lookups without leaving the page. Simply hold Alt (configurable) and double click a word, or select some text. A small inline box will pop up with the results of your search or lookup.
This extension works for any search engine or online dictionary, and allows you to easily specify your own sources. You can also specify default scrolling actions for each source, so when you perform a search, the pop-up will automatically scroll to the appropriate section of the page.
The icon is by Ken Saunders, taken as per the Creative Commons BY-SA license from: http://www.iconlet.com/info/27342_Question_128x128.
For a cleaner interface and faster lookup but less flexibility, try Dictionary Lookup:
For a similar extension with somewhat different features, check out DictionaryTip: