This plugin provides search functionality for your WordPress installation, through Google Site Search (aka Google Custom Search). It uses Google’s XML API, and thus requires an account that has access to it (ie you need to pay for it).
The plugin hooks in to the standard WordPress search form, so there is no need to change it (standard search widgets etc will still work). The plugin provides a basic template for the search results, but you can easily make your own if you wish to customize the output.
- Read more about Google Custom Search here: http://www.google.com/cse/
- Read more about the XML API here: https://developers.google.com/custom-search/docs/xml_results