Graphing tools? Please!

[Darrell Long]

Once again I find myself needing to draw some graphs, and once again I
find that I don't have any good graphing tools.  I have an OLD version of
spoof, which is probably the best thing I've seen.  I know there are
troff-based tools, but those really aren't very interesting -- or great
quality -- since I tend to write my papers using LaTeX.  What I would
really like is something that produced PostScript so that I could annotate
it using something like idraw.  Any pointers will be appreciated.  If I
get any great suggestions I will summarize.

Thanks, DL