ManipUni said:

That stuff is fun in school. Nobody knows anything about it in real life, yet everyone gets by...

Err.. not quite nobody. Many US corporations for which I've worked over the last ~10 years use UML; Class and Sequence Diagrams especially - Use Case/Activity Diagrams sometimes. The larger the development team, the more useful they seem - especially for communicating (at least) design intent. However, the quality supporting tools tend(ed) to be expensive and without them the effort does not seem cost effective - IMHO.