I had a narrow escape with my Clie PEG-T625C . I was at a school board meeting when we heard this high-pitched whining sound. We looked around and one of the teachers said 'Oh, it's just the pipes creaking' (as school pipes do).
However, it continued and we eventually traced the sound to the bottom of my chair leg where we found the pocket of my leather jacket trapped with my Clie inside. I was about to lament the death of my PDA but, when I fished it out, apart from a slight dent on the back, it was fine - not a mark on the screen - and has been working fine for the last couple of weeks.
So, let's hand it to Sony for building the Clie to withstand a 290lb load, albeit with a slight whimper! However, so as not to push my luck, I will try to stop my habit of rocking on the back legs of chairs.