Buy (or dig out of your closet) an old Wifi router and install Tomato on it. Its web interface lets you edit its hosts file which is then active for all the devices connected to it.

Except many of us don't have Tomato/DD-WRT capable devices, not to mention I can't be bothered setting up an additional router to my current two, flashing and securing it and then switching my devices over to it just to test something when this solution does essentially the same thing.

I know you meant your question rhetorically, but I believe you can add a proxy server to the iPhone and handle any hostname trickery there.

Edit: Proxy settings can't be global, but are assigned individually for each WiFi connection.

Or you can use xip.io and save yourself a lot of trouble.

Yeah but then you're into jailbreak-warranty-invalidation territory. Great for personal devices, not so great on corporate.

Why would adding a proxy server invalidate your warranty? Adding a proxy is built in to iOS.

Oh whoops.. misread parent as installing a proxy server, not configuring one to be used in the settings.

jailbreak it