Team J is happy to be a part of a burgeoning film community here in the DC metropolitan area. As mentioned elsewhere on this site, when making a film, you can't go it alone—besides which, it's not nearly as fun. So here's links to some folks who can help you make your movie magic.
(Note: this list is not meant to be either exclusive nor exhaustively comprehensive. Suggestions for inclusion are welcome: send them to resources@teamjabberwocky.com.)

Local Film Groups & Professional Organizations

• DC DIY Film Group
• DC Film Salon
• International Television Association, DC Chapter (ITVA-DC)
• Women in Film & Video (WIFV)

Additional Film Resources & Professional Organizations

• Filmfestivals.com
• iCom: Film & Video Production & Post Production Magazine
• indieWire
• Mandy: International film and TV production resources
• Production Wizard
• Production HUB: The Production Search Engine
• Shooting People

Local Casting Agencies

• Betsy Royall Casting
• Carlyn Davis Casting
• Central Casting

Local Film & Video Equipment (Sales & Rental)
(Currently compiling)

Additional Film & Video Equipment (Sales)
(Currently compiling)

Production Facilities
(Currently compiling)

Screening Venues
(Currently compiling. The DC Film Salon has a great PDF of "Downtown DC venues" available to Salon members. )