Review: Teamwork Project Manager
Teamwork Project Manager is a Web based project management tool designed for freelancers and small teams doing client work.
Because it is a hosted service, you don't have to install anything on your own server. You can start using the service within 5 minutes (and without a credit card).
Best of all, there is a fully-featured, free-forever plan that lets you test drive the service. The free plan allows up to 2 active projects and 5 Mb of file storage. For some consultancies, two active projects is enough, and they may never have to upgrade to a paid plan.
Bottom Line: Teamwork PM is a great alternative to Basecamp. It has more features and a friendlier pricing structure (more pricing levels means you can slowly ramp up to the plan that fits your current needs).