OP here - thanks so much!!!

Check out what Parktakes has for SN kids. They call it "Adapted Leisure Programs." They offer gymnastics, aquatics, etc. There' also a nice taekwando program.

http://www.fairfaxcounty.gov/parks/parktakes/

I think DullesMoms.com has a special needs section. I'm also signed up with Certifikid which emails deals on special needs activities and events.

Kennedy Center has sensory performances.

(As does the Puppet Company in Glen Echo--but I do not recommend these. The staff sucks.)

Imagination Stage

Friendship Circle fcmd.org

You might try the Howard Co. Autism Society (even if you aren't in HoCo).

Fitness for Health in Rockville MD has open gym night on Friday nights I think. You might look them up.

I know there are activities in MoCo but I don't know who runs them. Hopefully someone else will chime in.

I'm looking for a website or just any info you may have regarding special need events in the DC/MD/VA area. I would really like to find some Halloween events but I'll take what I can get. Last year we did the easter bunny event where they opened Frederick Co mall an hour early for children with autism.. so they could visit with the easter bunny without a huge crowd. We also like the sensory movies they do once a month at RIO. However, I would love to find some other things for my 4 year old to do. We really like the activities designed for special need children..I feel more at ease knowing my child isn't the only one.
Thanks in advance!!