Keep in mind that if we try and get together, daytime is going to be our best bet. Gwinnett Co. doesn't just turn on lights on all their parks for the hella of it. I know the park right up the street from the house has got 2 ball fields big enough for us, but they're sometimes open and sometimes not.

That's probably going to be the case most everywhere. Usually if there's a park for the kids (swings, jungle gym, etc.) then those fields around that park are left open. I know that Bethesda has 3 big fields that as far as I know aren't kept locked (they weren't last time I played there). I could go by there and check it out if need be. It's not too far from my office.