Given how technology has rapidly change the way things revolve around our lives, taking away a person's mobile phone at a work place doesn't add up for me.
As much as I hate the idea, I've actually worked a certain period in my life at a job where personal phones were put away till closing hours. I kind of reasoned with the rule back then because it was security related. It was a bank. And in the past, cases were recorded where staffs indulged in fraudulent activities like giving out customer information to outsiders, and in some cases, passing information to robbers on availability of excess cash in the bank via their mobile phones. This was understandable. But not all jobs are bank jobs.
Cellphone's or mobile phones are personal gadgets, and as such, everyone should be given the respect of holding onto theirs regardless of where they are. They are like a lifeline, your connection to the rest of world. Anything could come up like an emergency, anytime, which needs immediate communication. How will it be possible to get in touch instantly if you didn't have a phone close by?
It is of my opinion that every work place which has such rules should be stopped. Mobile phones are more than just fancy handy gadgets for entertainment, they're a mobile or electronic representation of every individual.