(FWIW -- This posting is via MS "Suggestion" feature, in turn reached via
Excel's help... so at this point I am totally confused about what the heck is
going to happen next -- submit suggestion? Post to usenet? Both??? Damned if
I can tell from this UI.)

Excel 2003 Chart continues to have a limit of 255 data series per chart, a
rather surprising kind and size of limitation in 2005, given gazigabytes of
memory etc. And a very nasty surprise if one has been counting on Chart to be
at least modestly scalable.

On big paper, with just a few points per series (generated via SQL query or
macro), it's very easy to need possibly 1000's of series. Particular example
here is for line charts and scatter charts (where each point occupies only
small amount of space).