Click curve to highlight?

[Brandon T. <bam...@gm...>]

Is there any way to 'highlight' a curve by clicking on it?

For example, if I have data plotted as a line, if I could just
mouse-click anywhere on that line and have it change to linespoints
until I click somewhere off of the line?  This would allow me to
temporarily see where the individual data points are without having to
redraw using linespoints.  Make sense?  I've seen this with other
plotting tools and it is very helpful.

Thanks