Lorna Mitchell has posted her second part of her "tips for [tech] event hosting" series (first part here) with some suggestions for the day of the event - those last minute things that might get forgotten.
As an organiser you should know exactly where you are going on the day and what you need. [...] As an organiser you see all the small behind-the-scenes crises, but if they are invisible to the average attendee, then you're doing really well.
She makes suggestions about the little things - ensuring name badges are ready, a posted schedule of the happenings at the event (not every event will have programs), check in on all of the tech like projectors, wifi and the like as well as keeping track of things like hashtags on twitter to see what people like and don't like more immediately.