You may scoff that the shape of a glass makes any difference to how a wine tastes. Think of it in this way. If you eat a bowl of warm chicken noodle soup, it's yummy. If you eat that same soup when it is very cold, it doesn't have the same impact. If you eat the soup with a big soup spoon, you can smell the full aroma from that spoon as you bring it up to your lips and sip in a large amount. If you tried to eat the soup with a fork, you'd only get tiny amounts on the fork tines and no aroma at all.
The key to glassware is the shape of the bowl. Remember, your tongue only sense sweet / sour / salty/ bitter. Everything else comes from your sense of smell. So the better shaped the bowl is, the more it "gathers up" the aromas so that you can smell them well. Also, many people like the feeling of a thin rim, so there is less "non wine" in their mouth :)