GWJ East Coast Slap & Tickle
Sorry, just trying to get your attention there.
So, NYC and DC have already been suggested. I'm very centrally located as far as mid-atlantic goes in northern DE, very close to philly. Unfortunately, I only have room to sleep about 3 or 4 people at my apt, but I do know of some cheap hotels in the area (it is Delaware, afterall). and I know some great parks nearby.
I'd also be willing to go just about anywhere between NYC and DC. That even includes Jersey, so you know I must be serious!
Let's figure out something, maybe late August or September?