Fire Ban Information: 
If a Total Fire Ban is declared in the Mount Lofty Ranges, you are not allowed to enter a forest reserve (or Eagle MTB park).
Information on daily fire bans can be found on the CFS website at SA Country Fire Service
Also the CFS website has information on the SA fire ban districts.
The Bureau of Metreorology website lists any current fire bans Bureau of Meteorology
Weather: 
Check out the Bureau of Metreorology website Bureau of Meteorology
MTB Competition Clubs:
Adelaide Mountain Bike Club 
Also the AMBC forum is a great place to hook up with some other XC riders AMBC Forum
Inside Line 
Inside Line, Downhill MTB Club
Also the Inside Line forum is a great place to hook up with riders Inside Line Forum
Escape Goat Adventures 
Mountain biking trips and skills training in Adelaide, South Australia and beyond. Escape Goat Adventures
I've done a couple of trips with these guys and highly recommend them. There's also some great info on their web site so check them out.
GPS Visualizer 
I've been using GPS Visualizer to convert my Megellan GPS data to google earth maps and also make altitude profile charts, it's pretty neat. www.gpsvisualizer.com/
