OpenOffice.org is a terrific suite of office applications in its own right, but it's out of this world when paired with extensions that add extra functionality. There are plenty of extensions to choose from, but let's take a look at a few that will really make your productivity soar.

Writer's Tools - You don't have to be a professional writer to appreciate this extension packed with loads of handy utilities. In fact, there are too many to mention, but here's a glimpse: Remote Backup lets you quickly shoot a backup copy of a working document to an FTP server, Quick Converter helps you perform metric-to-imperial system conversions on the fly, and the Lookup Tool checks word definitions from multiple online sources all at once.

If the terms "next action", "someday/maybe list", and "tickler file" mean something to you then you know about David Allen and his popular productivity how-to book, "Getting Things Done" (GTD). Predictably, the book has spawned loads of computer-based applications to help you organize your life based on Allen's methods and principles.

Thinking Rock is a great open source app for implementing the GTD system. Licensed under the Common Development and Distribution License (CDDL), it works on Linux, Windows, and Mac -- perfect if you run different operating systems at work and home. Once you set up your contexts (@home, @work, @market), it's dead simple to process your actionable items and create to-do lists. A large empty window helps you collect your thoughts and ideas, then plug them into the correct lists via a drop-down menu.