i take it you're not military... because that's the first thing that popped in my head. if somehow you can get on base and present valid id, you can play at any gym on any base, and they're all free.

other than that, schools is the only thing that comes to mind... which may be free to play at, but you'd likely have to know someone or know of some sort of special event to play in.

just pony up and pay the $35 a year or whatever it is now for a rec center membership. completely worth it... there is always an adequate level of talent during the 'adult basketball' sessions so you're almost guaranteed to get better, and everyone gets an equal time to play so there's no pressure to win or make sure you get the right personnel on the court if you want to play more so it's way more laid back than pretty much anywhere else you go.

after my intramural flag football season is over i'm going to be hitting up the rec centers again myself. i much prefer them over the bullshit favoritism that goes on at some of the base gyms.