To-do apps are notorious for being difficult to navigate and more time-consuming to use and manage than the tasks you may be trying to track. FolderBoy takes a different approach to helping you organise your projects, using folders to organise categories or projects and tasks that can live in multiple categories.
Part of what makes FolderBoy so useful is that it takes a very Gmail-inspired approach to managing to-do lists. You can create folders, but those folders behave more like labels, and the same task can live in multiple folders at the same time. You can also quickly and easily add ideas and thoughts that don't correspond to a specific task, but that you want to think more about later.
You can share tasks with other people using FolderBoy, drag and drop items, create sub-tasks and dependencies, and more. Best of all, FolderBoy is free. The service has an excellent step-by-step walkthrough to help you understand its features, so if you're looking for a web-based to-do manager that's easy to get started with, give FolderBoy a try.