Is UML Really Necessary?

rotifer asks: "A while ago I saw Kent Beck talk at the Java user's group meeting here in Seattle. Someone asked him about UML. He made a derisive noise and sneered that he had come up with a better version called GML, Galactic Modeling Language. He said (and I am paraphrasing here) that GML had three components "Boxes, Arrows and Arrows Pointing to Boxes". I thought this was right on. That seemed to be all the object modeling a person would need, especially when compared to the 808 pages of obtuse documentation that make up UML. But am I missing something here. Do people find UML useful. Or is it just overblown hype? Do you need this fully featured language to design an O-O system? Or are you better off with just boxes and arrows? Also, if you were to teach programming to beginning Java and C++ developers, is it a good idea to start with a course in UML so that new programmers can become familiar with O-O methodology before they start to cut code?"