In reply to James B:
> I'd like to spend some time in the desert among the Jebels, and possibly to walk or scramble in the Petra area if it isn't too full of tourists. I'd also like to stay at Aqaba for some diving -I'm thinking of using Arab Divers.
All very doable. You will smile to yourself when you go to Petra and wonder if it's too full of tourists. The Taylor/Howard book is excellent and the out of the way places they mention are particular highlights for me.
I haven't been for a while, but the Royal Jordanian diving centre a 20 minute bus ride S of Aqaba used to be the place. PADI trips are run from there, too.
> Is it possible to bivvi in Wadi Rum, or would the presence of snakes/camel spiders/hyenas/scorpions or other unfriendly or over-friendly desert creatures make for an uncomfortable night? Do I really need to lug a tent around?
Bivying out in the desert is one of life's great experiences and there is no need for a tent. I have once encountered a scorpion and unlike Australia, have never seen a snake. You might value a tent as a base.
> Are there any places north of Amman that it would be criminal to miss?
Jerash is pretty amazing if you are into that sort of archaeological thing, but that's the only place N of Amman that I've visited. If you haven't got time to go to Jerash, there's some really interesting sites in Amman, eg the amphitheatre.
> If you had 2 weeks in Jordan what would you do with it?
3-4 days in Petra and 10 days in Wadi Rum.