I commonly seek out event ideas that are unique and out of the box. I learned that Youtube is generally a good source for these types of tips. All you need to do is visit Youtube and perform a search for "birthday party suggestions" and you can find many hours worth of clips with many very good points. The issue is, who exactly has the amount of time to watch them all? So I am on a constant mission to collect some notes so as to save me and perhaps others some time.
Here is an awesome video with some crazy party ideas - https://www.youtube.com/watch?v=wUlJSgYGmFw
I hope you find a number of great tips for your next gathering on Youtube!