PhpReport is a self-hosted solution for time tracking and project management.
This extension is a front-end for PhpReport users. It adds a toolbar menu to your browser, from which you may create, update and delete tasks for the current date.
More interestingly, it can work like a timer: you can "start" logging time when you begin your journey, and "stop" when you finish. There are some convenience features: it will stop logging if it detects the computer has been suspended for more than 30 minutes, and it can continue an ongoing task after midnight, creating a task for the new day transparently.