It hasn't seen much use lately, but there is a private group on here, Sunshine Skate Society.
There is also a Facebook page for Brisbane called BFL (Brisbane Freeride Longboarding) or something like that.
There are usually guys getting out every weekend for freeriding and every now and again, for some downhill action.
Beware, groms will latch on to you if they know you have a car and they talk a complete other language. I don't know what they learn at school!
Hope the link works.
If you come up to Noosa on 26/8. Most of the crew will be there. Gynider Drive Tewantin.