Freework - An easy way to keep track of your daily work
Empoche - Utilities, Application Utilities, and Task Management
Hours - Boosting productivity through live, virtual co-working.
Klokki for Mac - Rule-based automatic time-tracking
Toggl - Toggl is an online time tracking tool. It features 1-click time tracking and helps you see where your time goes. Free and paid versions are available.
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.