This feature exists, at least partially. WorldView supports selection, so you ca select items in 3D and you can check the WorldView.SelectedItems collection. Selection is view dependant right now, however, which means that if you select something in WolrdView it doesn't show up as selected in the overhead map. That's because the overhead map would likely have a different way of showing that an item is "selected". In fact the Bing map control doesn't have the concept of a "selected" item. You would likely accomplish it by changing the items style.

With that in mind, it should be possible for you to make a class that inheirts from ARItem and add your own IsSelected dependency property. You would need to update the item style for each view to bind to that property. For example, you would need to data bind WorldViewItem.IsSelected to MyARItem.IsSelected. You would then need to update the style for a MapItem to do somethign with IsSelected too.

We can look at doing this work in one of the samples so you can see how it's done, but just be aware that the selection will need to be handled differently for each view.

I had done what you suggested, and it works very good. I have also add and event to it so i am aware of the click on the ITEM and do something. I have also add some functionality to your Simple AR app, to search for Geographic objects in a ArcGIS Server service Map containing a layer i can edit. So i see those objects instead of the random ones (like your bing app) and do something when i click on them in the ARDisplay. Thank you very much for all your help. I will follow this site and your blog for news. When i have a "desent" app (or kind of) i will post it in your site.