Nice time spent writing this up for people. Good job.
I passed my CMS Level 1 test back in '04.
Most established restaurants will decant a bottle for the reason mentioned aboved for "aeration". Meaning the decanter vessel has a removable mesh filter spout(glass or metal) that lays/sprays the wine along the walls of the decanter to give it more surface to air (and not aggitate the delicate wine) as it is poured in.
Opening a bottle and letting it "breathe" in the bottle or glass is not the same thing but similar concept. (The classic way of decanting a bottle can be done with candle light turning the bottle but no need to get into that.)
So for those reading, if you go to a restaurant don't just ask for it to be "decanted" thinking it means to let it breathe. If you ask to get it decanted you'll get the whole show and some wines don't really "need" it. Another tip for those dinning out and ordering bottles. If you know you are going to have a "big red" with your entree' go ahead and have it opened and left to breathe during your first courses. Start with something else before.
A tip for any novice thinking of buying a wine decanter. Understand that to get the wine out with a style like this, you have to turn the decanter almost completely upside down for the last 1/4. So be careful not to splash yourself or girlfriend trying to look stylish. I have three different decanters and aerators for friends and parties. I see it happen all the time on some of the designs.