I just got back from SYD and MEL on holiday, so I won't be joining you guys this time around, but I HIGHLY recommend the BridgeClimb. I'm not one who is normally known as the uber-adventurer, but that was THE most amazing experience. It's very safe, and if you don't mind heights, you MUST do it! There are only two bridges in the world that allow this - the ohter is in New Zealand.
Do it! You will not regret it!
- T