Goolge has added Custom Search to Knol that bring the speed and relevance, including advanced spell checker of their search technology. Now, when you search within Knol, the search results look a little different from Web Search results, see this search for knee surgery. “We were able to maintain that distinct feel for Knol search by taking advantage of the Custom Search XML results format (via Google Site Search) and creating the search result display that we wanted”. [Google CSE Blog]