The Omni Group today released OmniOutliner 2.1, the latest version of the company’s tool for outlining and organizing your thoughts on Mac OS X, as noted by VersionTracker. The update includes several bug fixes and improvements, all of which can be found in the release notes. OmniOutliner is available as a free version or a licensed version (US$30), which allows users to edit documents with more than twenty items.