I agree with others here who have said that dress codes in the workplace are a good idea for both staff and clients. Particularly clients. My girlfriends and I went to a restaurant recently, where one of the waitresses had her boobs out like you would not believe. It was a pretty casual restaurant and she looked very nice - all in black, hair back etc. But her breasts just popped out in your face and wobbled around when she walked. It's not that they weren't very nice breasts - they were!
But there were heaps of children in this restaurant and even if there weren't, I just don't think that's appropriate at all. None of us are prudes and quite frequently wear booby tops when we go out partying - but at work? We were all quite shocked and a little offended.
In an office situation, it's the same thing. You're at work, people, not at home or at the pub. A bit of decorum doesn't hurt. But as long as you look neat and tidy and you are dressed decently it shouldn't matter what you choose to wear.
I wouldn't wear my `rocknroll' t-shirt to work, partly because I work in a hospital but also because it's not appropriate, really. But when I worked in radio I definitely would have worn it. We didn't really have clients coming in and besides, it's radio.
We have a uniform at my work which is very nice, very comfortable, and really looks good when we all wear it. But we have a charity day every month and we can wear whatever we want. We pay some money to do so towards a nominated charity and we take it in turns to choose the charity. Our practice manager just has one rule for free dress days - `The Three Bs', she calls it - no boobs, no bums and no bellies. And fair enough, too!