This plugin adds a configurable search feature to blogs.
There are several options available for this plugin. First, there are the display options. This includes options to control the text and labels used to display the search box. There is also a setting to control where the search box is displayed: the sidebar, the banner (where the blog title is), or the menubar (where the sitemap is).
In addition, there is an option to set the search engine. There are currently three choices.
The Google and Bing searches, as you might expect, will simply do a site-specific search at those search engines using your blog’s URL. Whether or not that search actually returns anything will depend on when Google/Bing last indexed your site. Obviously, if they haven’t crawled your site since a post went live, that post won’t show in the search results.
The built-in search, on the other hand, is guaranteed to always have access to all your posts, because it is built right into the plugin and can access the data files on your server directly. The down side is that the search is pretty dumb (it does naive sting matching) and not particularly fast. For the typical blog, if you don’t get many search requests then the search performance will probably be “good enough”. However, if you start getting lots of traffic, you’ll probably want to switch to Google or Bing.