I often search for event ideas that are unique and out of the box. I think that Youtube is definitely a wonderful source of this sort of tips. All you will have to do is browse Youtube and perform a search for "birthday party ideas" and you can find several hours worth of videos clips with a lot of awesome ideas. The trouble is, who exactly has the amount of time to see them all? Thus I am on a continuous mission to gather some notes so as to save me and perhaps others some time.
Here is a great video with some crazy party ideas - https://www.youtube.com/watch?v=wUlJSgYGmFw
I hope you find several great ideas for your upcoming gathering on Youtube!