Google made some helpful changes to the Google Search feature in Gmail Labs. The search gadget now runs some of Google's most popular search features, like dictionary definitions, spelling suggestions, calculations, local results, weather info and news. You don't even need to type your search query anymore; just highlight text in the compose area and click multicolored "g" button to run a search on those terms.
- Dictionary definitions: use a keyword like "define" in English and you'll see first definition of the word, with a link to dictionary from which it came.
- Spelling corrections will automatically ask if you meant a more common spelling of that word (especially helpful when looking up a new word).
- Calculations: type in an arithmetic expression and you'll get the result. In this case the "Paste result" option from the result's pop-up menu will actually paste the result of the computation.
Full Article: Google Apps blog