Using wikis to manage software projects
blogs.activestate.com
blogs.activestate.com
In retrospect, I wouldn't track work packages and progress in a Wiki any more (instead use something that can actually add up the "time spent" column...), but the rest was fun to work with.
The old generation of online project management software (see: dotproject) was awful, had no UX design, and probably was less efficient than a wiki. However, new programs like basecamp and thymer are much easier to use and add a lot to one's productivity. Certainly, it is much faster for me to create a thymer account than it is for me to use a tool that isn't meant for project management in the first place.