If you need a todo list with timers that able you to time every tasks from start to finish, there is a web service that may able to help you. It is called ClockWork.
ClockWork is a time management solution that allows you to easily track what you do during your day. ClockWork is ideal for anyone who works with clients on an hourly basis, or needs a solution to track productivity for any task or project.
ClockWork allows you the flexibility to start, pause and resume an unlimited amount of task timers making it easy to switch between tasks without delay. You simultaneously run timers for multi-tasked projects, or easily switch back and forth between tasks, all without ever refreshing the page.
I don't tend to measure myself on a task with a timer, as in my opinion the administration on controlling timer maybe higher than each tasks that I wrote down on my todo list. However there maybe some practical usages. Let me know if you guys have any experiences on using timers and what are the benefits.