How do I create a continuous density heatmap of 2D scatter data in R?

I can generate a density plot of 1D data with:

qplot(mydatapoints, geom='density')

I've also seen plenty of examples of heatmap grids, but these are more akin to histograms for 1D data in that data goes into discrete buckets instead of showing a smooth curve.

Can I plot something similar to the 1D density but for 2D data, with (say) something like hue/saturation/lightness to represent the density?