Microsoft has released a new feature of its mapping services (requiring a download and install for Internet Explorer) that takes direct aim at Google Earth. I was half way through writing a post about how cool this is (and I still believe that it is, BTW), when it managed to crash my PC. After rebooting, I'm having major problems trying to run it again (I try to launch, it tells me to install it, I try to install it, it fails).
Anyway - as I've lost time with this, the details will have to wait for another post. The key thing to note is that Microsoft has gone for a level of detail in its 3d city scapes that leapfrogs Google's current technology. In addition, they are integrating advertising with this 3d world in the form of billboards.