Google Instant Searches the Web As You Type
Google has rekindle its love for speedy Web searches with Google Instant, a new version of the search engine that displays results as you type.
When typing a search query with Google Instant, results appear after the first letter is entered, and they update as the user types. Marissa Mayer, Google's vice president of search and user experience, said results are actually delivered "before you type," because Google Instant predicts and automatically completes search terms.
Google Instant is not just Google trying to guess at your keywords as you type them. It is Google starting to run a search as you type each letter.
Here is Google's page about Google Instant