Arrived at Petra on 21.03.08 at nite. Took the taxi direct from Amman airport,66 dinars with a driver called Falah (arranged through Miriam hotel in Madaba). Petra Palace hotel was my accommodation there for the next 2 nites and it was just 300m away from the visitor center.
A word of advice about visiting Petra would be to start really early before the tour group crowds arrive at 9+ am. The visitor center starts selling tickets at 7 am but I heard the gate allows people with tickets through at 6 am. So it might be good to prebook the ticket the day before. Latest info is that Petra by night is available on Monday, Wednesday and Thursdays. Pity I was there over the weekend and missed out.