Scrivener - the word processor with a cork board
Scrivener is a new word processor made for the messy, non-linear and notecard-slinging writers out there. Merlin Mann has been raving about it, and I can understand why: Scrivener's entire UI and workflow is designed around managing the pieces of whatever you're working on, allowing you to organize things like thoughts, outlines, pictures and dialog snippets with folders and keywords. The most interesting organizational feature, however, is a unique cork board UI on which you rearrange virtual notecards that contain summaries of whatever is in the document they represent. Hopefully, this allows many a college student and screen writer to stop jamming real cork boards in their bags when meeting for group projects.
Scrivener doesn't stop there: multiple document editing, full-featured outlining, full-screen editing and format-friendly exporting all round up quite a v1.0 debut. A 30-day demo is available, and a license runs $34.99.