This one is really nice — Google Co-op allows you to create a custom search engine and launch it from your own site.
Build and customize your own search engine:
* Specify the sites you want to include in searches.
* Place a search box and search results on your website.
* Customize the look and feel to match your website.
* Invite your community to contribute to the search engine.
* Make money from relevant ads in your search results.
* Learn more: FAQ and featured examples.
I have one right here: YugaTech Search.
So if you’re running a really huge forum like Motorcycle Philippines, you can use this instead and free your server of a ton of CPU load from index searching.
Just like Adsense for search, you can also monetize this search engine by adding your own Adsense Publisher ID.


Finally, a good article about this topic! I can’t believe I had to go thru like 20 blogs just to locate this good article. All their information jointly even now can’t equal the information of this post. I have learned a good deal and will bookmark your site. Keep up the good work!