Mobile social startup GoAct has announced the launch of Plango, a social calendar with Facebook integration that aims to make it easy for you to plan events with your friends.

Plango, which is available as an iPhone app and a Web-based mobile app, helps you to turn your ideas for social events into concrete plans with your friends. It does this through a social mobile calendar that features real-time SMS messaging and push notifications.

The service helps you to arrange plans with friends and family members through Facebook. You can access all of the events you have been invited to by your Facebook friends and send messages to those friends through the app.

Here’s a video that provides some more details about Plango:

GoAct recently raised $500,000 in funding from investor Esther Dyson, 7 Finnish angel investors, and the Finnish Funding Agency for Technology and Innovation (TEKES).

It’s a rather nice idea, but I have to wonder what will happen to Plango if Facebook decides to introduce its own calender system. After all, the social network has just made it a little easier for you to make plans with friends after it launched its dedicated Messenger mobile app Tuesday.

You can check out Plango for yourself by visiting the service’s website or downloading the iPhone app.