Add all your events to be reminder and invite others to meetings. Can merge many calendars.
A very popular option to manage your time, Google Calendar lets its users schedule events, send invites, define tasks, and share calendars. It easily syncs with all Google tools and will offer you timely reminders to help you keep track.
Completely free :)
From our blog
How to take better notes with MindMeister
Live mind mapping: A short guide to better note taking at events