DIVA-GIS

Check out BioGeomance Workbench - http://bg.berkeley.edu/latest/

What I like about this service, is that the size of points (synbols) on the map is determined by the lat long resolution, so the greater the uncertainty of the lat long value, the greater the size of the symbol (circle). What I also like is that the circles are presented not as solid colours, but with opacity in place.

It would be great if at a glance one can distingish between point data (I suggest as solid circles) and non-point data (provided as larger circles with opacity).

At the very least, such an opacity option for symbols in DIVA-GIS would be great, and even better would be an option to preset the sizes and opacity of symbols based on the values in a specified field (lat long resolution).