Meetio Room - Meeting Room Booking System
Todo.txt - Track your tasks and projects in a plain text file, todo.txt. A todo.
Resource Central - Meeting room & resource scheduling software for Outlook
Task Coach - Task Coach is a simple open source todo manager to keep track of personal tasks and todo lists.
Smartway2 - Book meeting rooms, desks & more via mobile/Outlook/desktop
Strikethru - Strikethru is a kind of to-do list notebook for managing work lists and staying updated with the important tasks.