Qantas take Paltinum One Frequent Flyers through the sims on 'flight experience' tours on a semi regular basis. You can purchase them with either frequent flyer points or cash. It's been a semi regular thing over the last few years.
Actually, it's free* for Platinum One frequent flyers - so far I've had 2 hours in the Essendon 737 and the same in the 747 at Mascot.
* OK, there's no such thing as a free lunch, lots of flight dollars went towards the P1 status, sadly now lost with retirement kicking in.