R help - Jun 2004 - Contour plots of PCA loadings

Hi,

I was wondering if there is a way of plotting smoothed contours of PCA
loadings onto a map. At the moment I have the loadings plotted as
positive/negative (red/blue) scaled circles centred around where the
physical stations are on a map - but I was wondering if there is a nicer
way of plotting this data, perhaps as contours of "regions of
influence"
or somesuch?

Any suggestions would be gratefully received!

Thank you in advance,
Laura