SearchTray is a search tool that speeds up web searching. Here's some of the features: Launch a search right from the desktop, without opening your browser. Search multiple engines at once. Search specialty sites like : Wikipedia and PubMed!! Saves your search query for faster searching on different search engine sites.
With the free version you can search yahoo, google and digg.
With the full version you can search many more search engines, including speciality sites like wikipedia and Pubmed