So here's the scenario - I wanted to watch a video on the iPhone in a quiet area (work). I opened up iPod, and used the volume button on the left of the phone to turn down the volume BEFORE I hit play. I now know, that all I did was shut the ringer volume off - so I missed some calls later in the day, no big deal.
Then I woke up at 8am. I looked at my iPhone and I had missed my 7am morning alarm! LATE FOR WORK
So, there it is. Don't turn the ringer volume all the way down when you are playing a video in the office because you want to make it look like you're making a call, as you'll be late to work the next day.
Feedback submitted to http://www.apple.com/feedback/iphone.html
Then I woke up at 8am. I looked at my iPhone and I had missed my 7am morning alarm! LATE FOR WORK

So, there it is. Don't turn the ringer volume all the way down when you are playing a video in the office because you want to make it look like you're making a call, as you'll be late to work the next day.

Feedback submitted to http://www.apple.com/feedback/iphone.html