Original User: rwelikalWell, you can make a TOOL or you can make a command.. a TOOL will initiate the code when you CLICK the map.I would draw a point on click using the ESRI snippet.    Public Sub DrawPoint(ByVal activeView As ESRI.ArcGIS.Carto.IActiveView, ByVal x As System.Int32, ByVal y As System.Int32)        If activeView Is Nothing Then
            Return
        End If
        Dim screenDisplay As ESRI.ArcGIS.Display.IScreenDisplay = activeView.ScreenDisplay
        ' Constant
        screenDisplay.StartDrawing(screenDisplay.hDC, CShort(ESRI.ArcGIS.Display.esriScreenCache.esriNoScreenCache))
        Dim simpleMarkerSymbol As ESRI.ArcGIS.Display.ISimpleMarkerSymbol = New ESRI.ArcGIS.Display.SimpleMarkerSymbolClass
        Dim symbol As ESRI.ArcGIS.Display.ISymbol = TryCast(simpleMarkerSymbol, ESRI.ArcGIS.Display.ISymbol) ' Dynamic Cast
        screenDisplay.SetSymbol(symbol)
        Dim displayTransformation As ESRI.ArcGIS.Display.IDisplayTransformation = screenDisplay.DisplayTransformation
        ' X and Y are in device coordinates
        Dim point As ESRI.ArcGIS.Geometry.IPoint = displayTransformation.ToMapPoint(x, y)
        screenDisplay.DrawPoint(point)
        screenDisplay.FinishDrawing()
    End Sub
Then I would use another snippet and use that point to get the click location:    Public Function GetMapCoordinatesFromScreenCoordinates(ByVal screenPoint As ESRI.ArcGIS.Geometry.IPoint, ByVal activeView As ESRI.ArcGIS.Carto.IActiveView) As ESRI.ArcGIS.Geometry.IPoint
        If screenPoint Is Nothing OrElse screenPoint.IsEmpty OrElse activeView Is Nothing Then
            Return Nothing
        End If
        Dim screenDisplay As ESRI.ArcGIS.Display.IScreenDisplay = activeView.ScreenDisplay
        Dim displayTransformation As ESRI.ArcGIS.Display.IDisplayTransformation = screenDisplay.DisplayTransformation
        Return displayTransformation.ToMapPoint(CInt(screenPoint.X), CInt(screenPoint.Y))
    End Function
Hope that helps.