This weekend, there’s an “inaugural” science and engineering festival happening on the National Mall in Washington, DC. If you’re from the area, or plan to be visiting, this looks to be an action-packed event to check out. It’s a veritable geek overload of speakers, exhibitors, hands-on workshops, and more. Over 1500 activities, 75 shows, four stages. Activities will be on The Mall, at Freedom Plaza, and Wilson Plaza. See the site for full details and a map.