HTML Cleanup

Suppose you have been stuck with a terribly messy html file (say, one generated by DreamWeaver or Microsoft Word). To clean it up, you need tidy:
http://tidy.sourceforge.net/
There are versions for unix, Mac, and Windows, both command-line and GUI. There is also an online tidy service here:
http://cgi.w3.org/cgi-bin/tidy (url only)