Along with the Social Media Club DC and Job Matchbox, 1 Piazza is co-hosting a Spring Social at the Science Club in Washington DC. You can read all about it, and RSVP, on the related meetup event page Spring Social w/Social Media Club.
Thanks to Larissa of the SMC-DC for the idea of a multi-hosted event.
Update – you can also register via the offical event page here: http://smcdcmarch.eventbrite.com/ so we can get a more accurate estimate of attendees.
Update 2 – also joining the co-hosting list, in addition to Job Matchbox, is the Entrepreneur Business Networking Group w/Sachi Studio http://entrepreneur.meetup.com/611/