Alternative desktop search engines for Linux are Beagle and Recoll. Such search tools enable you to easily find documents, emails, instant messenger conversations, notes, source code, images, etc. Besides the source code, binary installation packages of Beagle are available for most major Linux distros and can be downloaded here. Recoll downloads are available here.
Beta Release of Google Desktop For Linux Available
Google has released the Linux version of its popular desktop search engine Google Desktop. Both RPM and DEB installation packages are available. Google Desktop officially supports Ubuntu 6.10, SUSE 10.1, Fedora Core 6, Debian 4.0, and Red Flag 5, but will probably work on most modern Linux systems.