Google has released Google Quick Search Box for the Mac.

Google Quick Search Box is similar to Spotlight and QuickSilver, allows you to search for information locally on your computer or the net, and perform actions on the item such as launching applications, opening files or email documents.

To use Google Quick Search Box:

• Download the app from www.google.com/quicksearchbox/.
• Drag the app from the mounted dmg folder to the Application folder.
• After the app is launched, press Ctrl+Space to activate the search box.
• Enter your search text on the search box. Search results will appear as drop down list below the search box.
• Select the item from the search result, press Enter to launch the default action. For example if the item is an application, pressing Enter will launch the application.
• Press the Tab key instead if you want to choose other possible actions for the item.

Google Quick Search Box has an extensible architecture, developers can create plug-in to enhance its functionalities. For example, the Twitter plug-in allows you to tweet directly from Google Quick Search Box. But too bad you can not search Twitter stream from Google Quick Search Box.