Actually, you can the Google Toolbar site search even if the site has it own search engine to make use of the google operators such as quotes, the + or the -, all of which may not available on a site search engine provided by the site.
Download the free Google Toolbar, you will notice the Google Search box that is always visible on the Toolbar. In order to use this search box to do site searches, go to the Toolbar Settings, then choose Toolbar Options,, then click on the Buttons tab. Make sure there is a check mark next to Search Site.
It is not necessary, but you can use the Google operators for site searches:
- Use a plus sign [ + ] before words that you want to appear in your search results exactly.
- Use a minus sign [ - ] before words that you do NOT want to appear in your search results.
- Put a name or location in quotes so that Google will search for that exact phrase.
The Google Toolbar site search is something I use everyday. For more about Google operators and how to use them, go to Google Genealogy Tips.
You can also use the Google Toolbar to search a page.