Voo2do offers you to manage your to-do lists. Here’s a quote from their site that kind of gives you a good look of what they offer:
“What makes voo2do different?
Unlike most online to-do lists, voo2do tracks priority, due date, and time estimates for each task. There is no notion of “lists” in voo2do— tasks can be grouped by project, but you can view and edit a bunch of projects together. Voo2do supports some basic sharing of tasks”

With that in mind, here’s the main tabs once you login:

Voo2do tabs

The interface is quite “ajaxy”. What you do is add tasks to the tasks tab. You put the description, priority, due date etc. You can also e-mail your tasks to the list:

Voo2do tasks

Then you have projects. Each task can be put to a project. When you create a task you get a list of all your projects once you start writing in the projects box. You can then list the projects and see which tasks are assigned to which project:
Voo2do projects

Collaboration is possible in two ways, either you can collaborate so you can assign who is responsible for a certain task but you can also make your list viewable to public (or with a password…). Notes is a summary of all notes for all tasks. Deadlines is a summary of all tasks that have a deadline coming up. History is a list of tasks that has been completed.

Then there’s the Dashboard which gives you an overview of everything which you also can customize.

Voo2do dashboard

I like Voo2do. It’s playful and easy to use. However, it lacks some functionality like a calendar so you really need some other tool aswell to do the job to replace your “Outlook” or “Moleskin”. However, if you’re looking for a to-do list – check it out!