On TAPoR: http://tapor.ca/tools/86

Anthologize is a free, open-source plugin for WordPress 3.0. It enables WordPress to be used as a platform for publishing electronic texts in PDF, ePUB or TEI format. The plugin enables users to grab their existing blog posts, export content from external feeds or compose new content directly in Anthologize, then apply outlining, create a custom order, and edit content into a single document for export. Anthologize requires a self-hosted or local installation of WordPress.