Crowdspottr is an awesome application to help you out when you don't know where to go and whom with.

★ Explore upcoming events of your Facebook friends
★ Find popular events with your buddies involved
★ Use the Calendar to plan ahead easily
★ Bookmark events you’re interested in
★ Manage your RSVP directly from the application

★ Find places where your friends hang out
★ Discover the favorite places of your friends near you
★ Follow the checkins of your Facebook and Foursquare friends
★ Connect your Foursquare account and find popular places near you
★ Overview your friends checkin activity on a map

★ Grant special attention to friends to have a close eye on what they're doing
★ Hide those you’re not interested in
★ See your most active buddies