The Usuala Beach Hotel, a popular Hotel in Ibiza the clubbing capital of Europe has developed full online/offline integration with Facebook.
This post has been written by Julius Solaris for Event Manager Blog (?).
The Usuala Hotel example gives an outlook of a service you may demand from venues in the near future.
Here is a video of the experiment in action:
As the Hotel is fully packed with events you can see the immediate benefits of liking gigs or sending pictures tagged with the event name.