Google has released version 1 of the Google Desktop Search software for Mac OSX based computers. Google Desktop for Mac is a more basic version than its Windows counterpart, focusing on searching files, e-mails and Web pages. A “Quick Search Box” resides on the desktop and displays results to queries in a dropdown menu. (via)

Main features of this application are:

-It automatically indexes and allows you to search the full text of virtually all your files, including:

* Gmail
* text files (.txt)
* PDF
* HTML
* email from Apple Mail and Microsoft Entourage
* iChat transcripts
* Microsoft Word, Excel, and PowerPoint
* music and video files, including artist and song names
* Address Book contacts
* system preference panes
* file and folder names

Google Desktop also searches file types that have a Spotlight importer.

-Index and search GMail and Web history

-File Versioning is a very interesting feature like Volume Shadow Copy service of Windows Vista.
Google Desktop creates cached copies (snapshots) of your files and other items each time you view them, and stores these copies on your Mac’s hard drive. As a result, you can often use Desktop to find previous versions of your files or ones you’ve accidentally deleted.

Download from here