How cool is that, this guy wrote a sample web app that points his mobile phone location by using MapPoint and it's location server [COOL]:

MSDN Tell us a bit about Microsoft Location Server.
Lombardi We anticipate shipping Microsoft Location Server (MLS) in early 2004. The initial release is focused on enterprise customers who want to track mobile assets to solve business problems. MLS exposes its functionality through a SOAP API. The API has methods for managing privacy and contacts, and proxies to all of the MapPoint Web Service functionality as well.
  To illustrate, I built a simple Web app at http://www.whatididwaswrong.com/whereissteve. It displays an interactive map centered wherever my mobile phone happens to be. I created it with just five lines of Visual Basic.

[From the MSDN]