Contributed by: Don WinnerWASHINGTON - Following his second ``Night at the Museum,'' Ben Stiller is leaving a legacy at the Smithsonian Institution. The star of ``Night at the Museum: Battle of the Smithsonian'' is now also starring in a new orientation film for the museums on the National Mall. On Tuesday, the Smithsonian announced it has begun showing the 10-minute film continuously in the Smithsonian Castle visitors center. Stiller shows off some of the millions of objects on view in Washington, including the Hope Diamond and Dorothy's ruby slippers from ``The Wizard of Oz.'' The film also highlights research and conservation efforts at the National Zoo and the Smithsonian Tropical Research Institute in Panama. This summer's ``Night at the Museum'' is a sequel to a 2006 film.