I'm happy to announce a release of SmartBiller - a time tracking tool for consultants. It's implemented as an application which sits in the system tray and you just double-click its icon to start a timer.
There are 2 flavours available: Free and Professional. Professional edition comes with Plugin API so you can extend the application and integrate it with other systems. Free edition naturally has some limitations - namely number of timers you can run simultaneously, number of clients, projects and tasks. There's no time limit though. See feature comparison table.
Give it at try and see how you spend your day at work or on your own projects.