search for: equirectangular

Given a set of latitude and longitude coordinates pairs (stored in variables "latitudevals" and "longitudevals"), I would like to plot them onto the image of a equirectangular world map. I would like to plot each coordinate pair with a red circle, if possible. Does anyone have any suggestions as to how I go about doing this, whether using R or using another program like Google maps?   Thank you, Steve [[alternative HTML version deleted]]