Here’s one story of a bent iPhone and Apple’s response:

Following Apple’s instructions, I used my bent iPhone to schedule an appointment at the Apple Store’s Genius Bar for the following morning. I went to the store for my appointment, explained the situation to the employee, who then confirmed that the device was indeed bent without any obvious signs of abuse. I was then given a replacement iPhone and sent on my merry way. The whole process took less than a half an hour. From the time that I discovered my iPhone was bent to having a new phone in my hand was about 12 hours. Apple replaced the damaged phone under warranty at no cost to me, even though I had originally purchased the device from AT&T and not Apple itself. I’d never paid for any extended warranty or AppleCare Plus.

Your mileage may vary.