Color Bar enhancements?

I have also modified the colorbar code( in to

    > scale the width of the colorbar. I generate plots with
    > aspect ratios of x axis long with respect to the y axis and
    > in this situation the colorbar gets to be too fat.

The current implementation supports providing a custom axes for the
colorbar axes. Do you think it would be useful in addition to support
something like a fracw (fraction width) keyword arg for the default
width of the colorbar when making an automatic colorbar axes. If so
we should support this for vertical colorbars as well. Something like
fracax=0.1, the fraction of the axis (x for horizontal or y for
vertical colorbars) taken up by the colorbar when automatically
resizing the image axes.

    > The purpose of this long winded message is to advocate that
    > the color bar code be modified to make this facility an
    > option( ie specified color map, normalization, width
    > scaling and end caps).

    > I am willing to do this myself - but I would need some
    > help. Previously, John suggested that I make the routine
    > that does the fill calls derive from ScalarMappable. This
    > would make the colorbar color map and scaling come along
    > naturally. My skill level is such that I have not been able
    > to get this to work - I am willing but not very able. My
    > thought now is to make some substantial additions to
    > colorbar.

All of this sounds fine to me -- let me know how I can help.