My last cell phone was a Sony Ericsson z500a. I must have liked that phone, because when I was able to upgrade, I took a newer model, the z525a. The z500a, for all it's usefulness, had a very annoying feature: a dedicated camera button on the side of the phone that could be pressed by other objects in my pocket. I can't tell you how many times I took my phone out of my pocket to make a call only to discover that the camera was on and the battery was very low. I've also shot many pictures of the inside of my pocket.
My Pocket PC has a similar nagging problem. The hardware buttons get pressed while moving around in my pocket and strange things happen, appointments get created, I get audio recordings of my pocket, but above all else my battery drains.
My video iPod, by contrast, does not have this problem. Why? Because Apple, which above all else is great at design, included a lock switch that prevents accidental turn on and operation while being carried around in a man's overcrowded pockets. This lock switch is at the top of the device opposite the headphone jack and is firm enough that it isn't likely to toggle when brought into contact with a Swiss Army Knife or change or other pocket sized consumer electronic device.
What I wouldn't give for a simple lock switch on my phone and Pocket PC...