Update: June 2012 - This module is nearly completed although needs some updates for full compatibility with RavenNuke v2.5. I'll look to fit this in sometime in the coming weeks, as time allows... Noting that there are several other projects currently in the works that may take precedence.
Kudos to Tutorialzine for their excellent tutorial Google Powered Site Search with jQuery, as we have ported this as a ready to go theme-able module for your RavenNuke powered website. Use the power of Google Ajax Search to dynamically search your site for content, images, and/or video. See the included install.txt for setup instructions and additional info.
UPDATE: Some unfortunate news as Google has deprecated the Web Search API, so this module will likely no longer function correctly after 11/2013; and the number of search queries may (or may not) be limited at some point.