Zen Panels

Creates a panels layout that slips silently into the Zen theme, giving pages that look identical to any other site page but have the magic of panels underneath.

In other words, this provides a 3 column panels layout, but inserts each columns content into the existing Zen theme columns. This means you don't have to maintain 2 completely different 3 column HTML/CSS layouts (each with their own quirks), yet you get the additional flexibility of using panels to place content and route arguments/context - and are still able to create and/or configure completely different layouts when you need them.