You never think it's gonna happen to you..I've brewed 30 batches and never had to wait this long for activity. It usually start rocking after 12 to 18 or so hours. This was the first time I brewed at a friends house and waited until I got home to pitch the yeast. What I didn't do when I pitched was aerate the wort. When I brought the fermenter in from the car, It sat for a 1/2 hour or so. I shook the vile and just pitched.
Anything I can do to wake my friends??