Gubb.net: Make and share to-do lists online for free with this web application. E-mail a list to yourself or others, or text it to your cell phone. Sort it by priority or due date.
MyJobsToDo.com: This online tool is perfect for managing projects. Group different tasks by project, attach deadlines for each, and still see everything in one list. Clicking on any item launches the job.
To-do list widget: Since they live on your desktop, you can add or delete widgets or move urgent items to the top of the list, or tag it with a color. Download it at www.widgetgallery.com.
Todoist (todoist.com): Another good-looking, free, web-based calendar and task manager. Nice feature: its ability to nest items and create sub-to-do lists.
HiTask (www.hitask.com): Put to-do lists, projects and calendars on the web, where you can share them with colleagues.