There are several nice solutions out there for project management. The size of the tool required depends on the size of your project. The number of tasks determines the type of tool needed. If you have a truly giant project, you should consider tools akin to Microsoft Project. Most website projects can use an intermediate project manager. One of the first popular solutions was Basecamp, http://basecamphq.com/. There is an open source ColdFusion project manager that runs similar to that solution and that is the tool we have chosen to use at this time—Project Tracker. I personally don't use time management there because to me, FreshBooks is so much more powerful.
Visit the FreshBooks website at http://www.freshbooks.com/.
This tool crosses over the territory occupied or served by Project Tracker:
The benefits of each are good enough to convince me to split the use of each. I love the invoicing of the customers and the ability to track time on my iPod Touch via miniBooks. We have also started a project to create a CFC that interfaces with their web facing API if anyone is interested. This CF-side tool will be free via RiaForge. Oh, this can be used as an alternative for QuickBooks and other accounting solutions for many shops.
Visit the Project Tracker website at http://projecttracker.riaforge.org/.
This tool offers many unique advantages over e-mail thread-managed projects. With this tool, there is project visibility between team members. The project owner to the task worker, all get a view of what is going on. Files can be collected in a common location and to-do lists are related back to milestones. It is possible on files, messages, and most items to open a discussion. Unlike e-mail, this stuff stays collected and related.
This tool also allows multiple projects with specified clients, team members, permissions, and more.