I'm not sure why I didn't have that "aha!" moment when I first found this free, open source software. Given the insane number of products I look at pretty much every day, however, it probably was a case of getting lost in the noise. That's a pity, because it turns out TiddlyWiki is an amazingly, perhaps insanely, great tool. In fact, I award TiddlyWiki 10 out of 5 -- it's that cool.

While I'm sure all of you know what a wiki is, here's from the Wiki mother ship, Wikipedia: "A wiki is a page or collection of Web pages designed to enable anyone who accesses it to contribute or modify content, using a simplified markup language."

TiddlyWiki takes a more personal approach to wikis than most implementations, because rather than servicing a group of users -- or, as in the case of Wikipedia, the entire galaxy -- it provides a private, single-user wiki.

TiddlyWikis can be used in a number of ways, for example, as an elegant and low-cost method for creating, distributing, and collaborating on documentation. Check out , a TiddlyWiki that covers key concepts in the analysis of reasoning for philosophy students. You can use this TiddlyWiki online or download it -- and that leads to a key attribute of TiddlyWikis: Once you have your own copy, you can annotate and add to it, making it your own content mashup.

Another interesting use for TiddlyWikis is as a tool for implementing a (GTD) methodology. (I recently found out that the creator of GTD, David Allen, lives just a few miles away from me. Who knew?)