Trailers are notoriously tricky things; they can show you an extremely skewed version of the movie at hand, or they can give the whole movie away. The Weinstein Co. is trying another tack to get you to watch movies -- by giving you an extended teaser: they're showing free samples of select films online at video-sharing sites like YouTube. They've shown the first eight minutes of Lucky Number Slevin on the amateur site (after the movie has already opened in theaters) to get you to see the remaining 102 minutes. First Look Studios has given an extended clip of their period drama The Proposition, starring Guy Pearce and Emily Watson, to iFilm.com. The film opens in theaters on May 5.