Google's Ad-Free Site Search
You have a clean, attractive website. But you also have loads of content and pages that your visitors may need help finding. Previous versions of Google Custom Search would allow you to place a search box on your site - albeit with Google branding and AdSense all over the results page. Google's Custom Search Business Edition now includes ad-free search, where you can employ a Google search box on your site to search only those sites, pages or portions of your website that you determine. After a search query is entered, only results will be returned, not Google ads that can disrupt the feel of your website. It's a nice way to use the power of Google site search without sacrificing your site design or exposing customers to ads that may cheapen the look of your site or worse, drive traffic away. And, some can argue, AdSense on your site gives visitors the impression that you're a small-time business, looking to coax as much revenue as possible from your website.
Simply sign up, customize your search box, add the sites to be searched and get the code to place on your site. The fee is on a sliding scale, starting with $100 annually for searching 5,000 pages and up to $500 for up to 50,000 pages.