Good idea! You'll need a clearance to go to games, but pretty much everyone who goes to P-nats games already has one. Fireworks might bring in the Navy SEALs, but that will just add to the atmosphere.
Is the courtyard in the pentagon big enough for a diamond? It has this great parking lot, lots of commuter options, and if DoD is going to take a whack in any budget deal, then it will have some unused space there.