Turtl - The secure, collaborative notebook
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.
Tomboy - Apps/Tomboy - GNOME Wiki!
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.
Carnet - Opensource rich text note taking app
RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.