One of the great things about the Firefox browser is its ability to add functionality via plug-ins. There are zillions of excellent plug-ins available for Firefox, and one of my favorites is Googlepedia, a mashup between Google and the Wikipedia.
Googlepedia modifies the behavior of the little Google search box in the upper right hand corner of the Firefox window. When you type in a search phrase such as "rickets", the result comes back in a split window. On the left hand side of the split is the usual Google result for rickets. The right hand side of the split window shows the Wikipedia result for rickets.
Since the answers I need are often on the first page of Wikipedia, Googlepedia saves me the trouble of clicking through there for quite a few of my searches.