I'm working on what will become an interactive online map showing things like municipal services and leisure activities in a certain area. They exist as Points, and are categorized as 'police station', 'school', 'exercise - swimming', etc. Each category has an associated icon, by which the items are currently symbolized. There are often concentrations of several items in close proximity, so that at a scale of, say, 1:10,000 (quite reasonable for my purposes), they can become a bit of an incoherent muddle (not to mention the symbols tend to occlude the items' precise locations).
I'd like to be able to float the icons off to the side, with lines leading to the points themselves, or at least group close-by items of the same type together, as in this mock-up. There is a similar functionality for labels (at least as far as non-occlusion goes), but I haven't been able to find such a thing for markers. Clustering like in this example would be great, but I don't want to lose my categories while doing it. The final application is going to be built with the Flex API. Is there a good way to do this in ArcMap, or should I be looking towards Flex for this functionality?
(by the way, that's not what I'll be using as my background map in the end; the raster just draws a lot faster than available basemaps due to the projection I'm using.)