Mind mapping tools are among the unsung heroes of project management. They're often overlooked or underused because some people mistakenly believe the learning curve is too steep or the features are unnecessary. Most mind mapping software is easy to use, however, and the applications are a great way to keep track of projects, research, book notes, and brainstorming sessions.

Here are four open source mind mapping apps to help keep you focused on your projects and collaborate efficiently with others on your team.

I was just reading through an interesting post from Mike Kavis, in which he describes his efforts to use open source software as a way to avoid Microsoft's products altogether. His post is a follow-up to another one he wrote about his, er, social experiment. Kavis became Microsoft-free by using products such as Thunderbird for e-mail, OpenOffice for productivity apps, and Firefox for browsing. After chucking Microsoft Office, though, Kavis laments that "there is no answer for Visio." I beg to differ. There is actually a truly fantastic free, open source alternative to Microsoft's visualization and diagramming tool: Dia. Take a look at it here.

How many ways are there to manage your task list? Almost as many as there are people with tasks to do. Here are 20 different ways of tracking your to dos, with examples of each.

You probably use more than one of these options, depending on what you're trying to manage and what suits your temperament. Or maybe you have some other ideas. If so, share them here.