Artomatic in Arlington through June 23
If you haven't visited Artomatic yet, you really should. There's still plenty of time - it runs until June 23 and features more DC area artists than you can shake a stick at (around 1,100 of them, in fact). Plus there are many fun activities and performances, including workshops for children and adults. Have a look at the website for lots more information.
June 16-17 Old Town Arts and Crafts Festival - Alexandria, VA
July 1 First Sunday Arts Festival - Annapolis, MD
October 6 Art on the Avenue - Alexandria, VA
October 14 MPA Artsfest - McLean, VA