Today’s featured promo on MacUpdate offers Opal 1.0.9 for US$15.95 (50% off, retail $32). “Opal is an outliner. It lets you organize just about anything — ideas, reports, lists, notes, projects, graphics — as an outline. It stands out for its uncluttered, fluid interface. But Opal includes features not found in other organizers.” Opal 1.0.9 requires Mac OS X 10.4 or later.