My nephew requests the coolest parties. When he was two, he asked for a bagel party. For his fourth birthday, he said he wanted a flashlight party. I made a simple invite that was emailed out via Paperless Post.
My sister made this flashlight garland.
I made these quick kraft favor bags; flashlights drawn on the bags with a Sharpie.
The favors included a hand shadow puppet guide with a silhouette of my nephew I drew for the cover.
There was a dance party in the dark, flashing light rings, and a puppet show by the kids, starring a subway car, a fish, a giant bird and Thor. Read more about the party at my sister's site here.