A novel method is demonstrated that allows semantic and well-structured knowledge bases (such as DBpedia) to be easily queried directly from Wikipedia's pages. Using Swipe, naive users with no knowledge of RDF triples and SPARQL can easily query DBpedia with powerful questions such as: "Who are the U.S. presidents who took office when they were 55-year old or younger, during the last 60 years", or "Find the town in California with less than 10 thousand people". This is accomplished by a novel Search by Example (SBE) approach where a user can enter the query conditions directly on the Infobox of a Wikipedia page. In fact, Swipe activates various fields of Wikipedia to allow users to enter query conditions, and then uses these conditions to generate equivalent SPARQL queries and execute them on DBpedia. Finally, Swipe returns the query results in a form that is conducive to query refinements and further explorations. Swipe's SBE approach makes semi-structured documents queryable in an intuitive and user-friendly way and, through Wikipedia, delivers the benefits of querying and exploring large knowledge bases to all Web users.