MPSuperShape is an excellent add-in for Microsoft MapPoint that allows you to combine and intersect shapes.
    Working with Microsoft MapPoint becomes easier with this add-in that server the purpose to easily Import, export, and copy shapes between maps. This application makes it possible to combine multiple shapes into one large shape, find the intersections between shapes, find boundary shapes around groups of pushpins, simplify shapes, delete multiple shapes, import/export shape files, and to create web pages. The capabilities of this program can be applied to: combine drive-time areas to find the total area covered by existing depots, find territory overlaps, find areas which meet multiple characteristics, find territory boundaries around groups of customer pushpins, transfer shapes to/from other GIS systems, create web-pages from MapPoint shapes and pushpins.
    MPSuperShape, this amazing tool support GML and KML import and export options.