I routinely look out for event ideas that are unique and out of the box. I find that Youtube is without a doubt a great source of this sort of ideas. All you have to do is browse through Youtube and do a search for "birthday party suggestions" and you will see many hours worth of videos clips with a large number of fantastic tips. The problem is, who exactly has time to see them all? Thus I am on a continuous mission to put together some notes to save me and also perhaps others some time.
Here is a great video with some insane party ideas - https://www.youtube.com/watch?v=wUlJSgYGmFw
Hope you see a few good tips for your next event on Youtube!