The iOS Simulator uses the host machine network so you should be able to just use localhost or your machines IP address, whichever IP your web service is listening on.
So, try out this:
http://localhost:8000/your_path
Vra
iPhone Simulator can not open (localhost) http://127.0.0.1:8000/foo/bar/
What is the reason?
Oplossing
The iOS Simulator uses the host machine network so you should be able to just use localhost or your machines IP address, whichever IP your web service is listening on.
So, try out this:
http://localhost:8000/your_path