"Some of our more successful hackathons have been dependent on how we set up the space we work in," Keyani says.

Find a conference room or space big enough to comfortably fit everyone participating in the hackathon, he says, especially since they'll be there for hours. Facebook outfits its space with couches and beanbags so employees are comfortable--and plenty of whiteboards so teams can document ideas and progress.

Facebook kicks off all hackathons with a motivational speech. "We want to remind employees what this is all about and which company values it reinforces," Keyani says. "You want to remind them about the company they're working at and what it stands for. Every company will have a flavor of that."