Auto-generating an index

I have a medium sized document in docbook xml format.  I want to make
an index but am too lazy to go through it manually for a first order
cut.  I would rather auto-generate one and then fine tune it as I have
time.

Before I lay out my proposed method, I don't want to reinvent the
wheel: does anyone have any pointers to any auto-indexing tools for
DB?

Thanks.

-Tom

Thomas M. Browder, Jr.
Niceville, Florida
USA