Track2TimeIt for

From Toys for Bob:

This PDA program allows you to easily log how much time you spend on various activities. Events are easily timed with a single pen-click. Use it as a consultant's timer for your business or figure out how long you really spend in front of the TV. Your timing data is available for visual inspection in tabular and graphical form, and can even be exported outside the program; ideal for logging billable hours for submission to your clients. Track2TimeIt will simultaneously track any number of activities.