Asana - A hybrid task and project manager that runs on mutiple platforms. Add details to tasks such as links, comments, tags, and uploaded files.
Trello - Manage your project using a post-it note like interface. Drag and drop images, notes, files, and assigned tasks to organize the work.
Gantter - A GANTT chart generator that is intergrated into Google. Easy to share charts but no online collaboration features.