My stuff: What about a relay team challenge on emulators (with no hacks obviously)? You get on a team with like 4 other people, and each person goes through 2 gyms (the fifth beats the elite four). Each leg would have a specified starting time, and so people could sign up when they know they wouldn't be busy.
Wouldn't mind hosting this one if it gets approved, possibly participating. But I don't know much about emulators, so I'm curious as to how this would work. Feel free to message me about it or something so we can discuss, though. It seems really fun. :)