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.
WiseTime - Web-based automatic time tracking software
Hours - Boosting productivity through live, virtual co-working.
TimeSite Pro - TimeSite Pro is a fully configurable, cloud-based time tracking, expense & invoicing solution.
Futuramo Time Tracker - Futuramo Time Tracker is a time tracking solutions designed for freelancers and teams.
OutlookTime - OutlookTime is a time tracking system that turns Outlook into a timesheet system.