I'm writing an iPhone app as a hobby project and it will need a web service to provide it with data. It's not very different from what I do at work, but at work I only write views and controllers. Someone else is responsible for writing the model and usually the clients provide the web service.
I have done some web programming before, back when everyone were using MySQL and PHP, so my skills are a bit outdated, but I'm confident that I would be able to pull it of using the techniques I already know. However, I don't want to waste my time using obsolete tools. I've figured out that the state of the art would be to write a REST API. I was thinking that there should be some pretty good frameworks out there that pretty much just gives you a REST API with CRUD functionality as soon as you've defined a model.
I guess my question is: What would be the fastest way to get a REST API up and running? I really just want to focus on writing the iPhone app and not spend too much time on this API. It would be great if I could get web administration and revision history too. I should also add that the API isn't supposed to be public, so support for authentication would be great as well.
Just to be clear. I wouldn't mind a PHP framework. In fact it could possibly be better since I know that my current hosting supports it.
Just to let you know:
I ended up using Ruby on Rails.
EDIT: Since this answer has been downvoted for not providing the reason behind choosing Ruby on Rails and also no instructions on how to write a REST API with it, I thought I would give you my motivation and some simple instructions.
I started reading a book about Ruby on Rails and realized that all I needed to do was to use scaffolding and I got a JSON REST API for free.
Here's a good guide to get you started: http://guides.rubyonrails.org/getting_started.html
When you have your Ruby on Rails environment up and running, creating your REST API isn't harder than running:
(Example from the above link.) I also found that Rails is very easy and free to deploy to heroku, which meant that I didn't have to pay for hosting for my very basic, low traffic, REST API. There are many other reasons why I am very happy to work with Ruby on Rails, but that's beyond the context of this question.