UML tools

Take a look at this toll for UML drawing UML Graph:
Java UML tool http://www.umlgraph.org/
Python UML tool http://pypi.python.org/pypi/PyUMLGraph

Write UML as you code

Below is the link of site where you could write your UML as you code.
It is very interesting idea, take a look:
http://www.codeuml.com/