A local Dad has just released a FREE iphone / android app with a guide to Brisbane's Playgrounds for kids ... with a cool invitation feature to allow to invite friends to playgrounds meet ups and save them in your calendar http://www.lilarcor.com/

Playgrounds in Brisbane App
The Brisbane Playgrounds app allows you to browse over 1000 Brisbane playgrounds and use the rating system to work out which ones match your needs. You can also send playground invitations to friends and save them in your calendar.