[grantismo]

How about this for motivation?

You assign a due date and a dollar amount punishment when you create a todo list or task. When you fail to complete your tasks on the due date, your account is charged the punishment amount.

"How do you verify that the task has been completed?" you might ask.

You don't. If users "cheat" then they're just losing out on the motivation service, otherwise you get the motivation required to do the task on time.