How to draw a tree/graph of a web site?

(I just posted this to comp.unix.solaris -- but
since there might well be some perl trickery
for doing this, I'm posting it here too.)

Some websites, designed perhaps as pure trees, I find
difficult to use -- especially when the interesting pages
might be several levels down in the tree, with no hint
above that such pages even exist.

(Assuming that the a href names of the pages
do give a hint of their contents),

, it might be a big help to be able to see a drawn
tree or (directed?) graph of the whole site.

Any comments on this idea, or hints on how to do it?

Thanks!

David Combs