Depends on what you're looking for...there are tons of options.
We use basecamp to keep track of to do lists, stuff in progress and 'tasks completed'. There are some other ones out there as well that are free or cheap.
You can also setup something on Google Docs and then share it with a team, in excel or document format.
At one point, we used Wave as well to manage a few things, but the software isn't really project management oriented.
http://funadvice.com/r/151r15cdsjh - project management software organizes people and projects by simplifying, centralizing and accelerating access to critical up-to-date information. Vertabase project management software facilitates management by providing a framework for increased productivity.What's the best web-based free website builder?
I had a good experience with EMMI Soti Project management software. It's cloud-based and especially good for field services.
Check out this project management app for architects: