Ask YC: What do you use for time and todo tracking?

I'm working on a startup with two other guys. We need a way to efficiently keep track of who's doing what. At the moment we're using Trac and we're not really happy with it. Adding new tasks (tickets) is klunky, and tracking time (to predict whether we'll hit our deadlines) doesn't really work either.

I've looked at a lot of different software packages, but none of them are very good. Okay, Basecamp is good, but it's really targeted at the service market. E.g. web-designers or contractors. People with clients and billing and that sort of thing. What I'm looking for is project management for startups. Emphasis on TODOs, milestones, time tracking, and a wiki. Adding tasks to the system should be more convienient than writing on a piece of paper (or in a vim window) - otherwise the system won't stick.

What are you guys using, and are you really happy with it?