pgsql/jdbc schema viewer needed

I have a pgsql 7.0.3 database with JDBC installed.  I need to graphically
view the schema and would like to get ER diagrams or something useful like
that.  I've used pgaccess, but i need something that lets me see the
relationships between tables, etc.  something along the lines of Visio would
be great.  if it ran on windows, all the better.

i'm sure this is a FAQ, but i didn't see it in the FAQ list and the gizmo
for searching this lists archives seems to be broken.

i believe there is a free utility that does this for any JDBC database, but
I've been unable to find it with google.

thanks in advance,

---Matt