The world of search engine grows up every day. In addition to Top Search Engines I found this post added by ReadWriteWeb concerning Earth Day to introduce 15 best Green Search Engines. The search engines are all nice work.
- Green Maven
- Green Link Central
- Green Terroir
- Friends Green
To see the screenshots and get more information about each of these Green Search Engine, you can read more on ReadWriteWeb.
Read also about Earth Day on Wikipedia.