Sounds like an interesting activity. I hate to put a damper on your idea BUT what about locations in longitude; would people from ME have an edge on all the others? Someone could spot the new Moon crescent along the eastern seaboard up to 4 hours before someone on the west coast could, assuming all were looking for it at/after sunset.
For what it's worth, I'll be looking for it anyways, as I usually do, just for the fun of it
Mr Q