Things that would be nice to have done, but may be difficult to do.

Some way to tell in the window what the scale division lines (as
selected by the -scale) arguement are.  Writing them along the left
edge would require that the entire graph be redrawn, or a smart way to
erase the values and then redraw them.  Perhaps they can be written at
the bottom of the screen, as another number after the scale of the graph.
Ie, "disk	20/5" would should that the scale of the graph is 20,
but the division lines are drawn in increments of 5.

Storing all -type values for all hosts, and allow switching of the graph
type (by keyboard).  This will cause more memory use and probably also
more cpu use to set and store all these values.

