There are dozens of social networks in the world today. They’re doing different things, and have different reach. Some of the networks might not even look like a social network if you’re just thinking about Facebook, but that’s exactly what Wikipedia is too, when you think about it.
Trumba – A shared calendar and social events communication software, Trumba allows a great degree of customisation to users, and links to other networks and email so that your associates and friends do not need to be on it to get alerts and reminders for events and meetings from you.
You can also publish the calendar on the web and share it online if needed, but the product is not free to use.