I do repairs on iPhones so I get all kinds of stories from people about how they broke their phone. The best ones are when their dog has been chewing on it and they find it later on the floor with teeth marks all over it suprised the dog didn't get injured chewing on the glass!
I've actually never broken any of my own iPhones, I'm far too careful.
Same have never broken any of my iPhones tho had to take two in, one was a battery issue other multi touch stopped working in certain areas of the screen couldn't it send on SMS drove me up the wall...
Never broke my before, but I did had to replace my original unit twice, my original the GPS was screw up, my 1st replacement had some dust behind the glass screen, and my current replacement seem to be having reception issues, cause every time when I hold it, it drops 2 bars and sometime to 0 bars on 3g.