If you're new to Tulsa, swing by LaFortune Park to check things out. There's really something for everyone.
I go there to get some excersise... they have a 3 mile walking/jogging track that runs around LaFortune Golf Course.
They have a ton of playground equipment for the kids... it's like a Chucky Cheese experience
Also, lots of covered pavillions with grills & tables. All free, you just have to reserve them thru the City (www.cityoftulsa.org). It's a great place to have a BBQ with a big group.
And of course, the LaFortune Golf Course is an inexpensive public course. I think it's about $12 to play... not bad!