Theres probably a fair useage policy with the "unlimited" statement so be wary.
Just rang Orange they can't get anywhere near the prices ive found on the net for the HTC Touch HD and because Orange are the only people to have the HTC Touch HD that means i cannot transfer my number if i take out a new contract via the web. Which means G1 here i come.
Cheapest contract i found for the G1 are here if anyone is interested.
http://www.buymobilephones.net/mobile-phon...1-Black/85,8058
And cheapest HTC Touch HD deals where here
http://www.mobilerainbow.co.uk/alldeals.asp?id=1477
You can port your number across at any time of the contract. Be it in the 17th month of the contract, you can still do it providing its an active number on a network and your pac code is still valid.
Unfortunately you dont always get as good deals as taking out a new umber with the network, so best thing to do if you want to keep your number is port across to another network on payg and then port across to the network you'd like the handset on. You do not need the pac code before setting up another contract. As I said, there is no time limit on when you can transfer a number across.