I am displaying ScatterSeries data and it happens routinely that some of the data points in these series will overlap - either they are "really close" or actually exist at the same X/Y position.

Right now I use the SeriesMouseLeftButtonUp argument data to determine which series/item was clicked and that works well except for the situation I mentioned above.  What I'd like to be able to do is do some sort of hit test and do something meaningful with those overlapping points such as displaying them in another pop-up chart so that the user can choose among the points.

Do you have ideas about how I might perform a hit test?  I may have overlooked an example of this situation that was posted elsewhere.  I'm assuming I'm not the only person to have to handle this sort of thing.