Adobe Air: Pomodairo is a timer and task-management tool based on the Pomodoro technique. In addition to just timing your Pomodoro sequences, it tracks your tasks, how much time you spend on them, interruptions, and your productive (but unplanned) work.
Pomodairo can serve as a simple Pomodoro timer (25-minute blocks of work and the accompanying breaks) but it does so much more. You can track tasks, see how much time you've spent on them, mark interruptions (tracking daily interruptions is part of the Pomodoro technique) and sort your tasks based on those factors.
Pomodairo is cross-platform thanks to the Adobe Air underpinning and can be synchronised between computers you work at. Pomodairo is a free download and works wherever Adobe Air does. Visit the link below to grab a copy or read up on the Pomodoro technique here.