This one does not necessary fall under Mid-Market or partner space, I just thought it was worth mentioning.

 

http://dev.live.com/virtualearth/sdk/

This site allows you to walk though various scenarios of navigating the map, adding custom locations, views, directions, and even display 3-D birds eye view (if available).  After you have a view you can display it on your blog, webpage, in an application and so on.  

One idea would be to create a collection that has all the various location of a company using push-pins to display those locations.  Each push-pin could be edited to show information specific to each branch.  When a user hovered over the push-pin the info could be displayed and then could act on the information displayed i.e. phone number, driving directions and so on.

Just to give a better idea, here is a collection I have created with events I will be competing in in 2007.

http://local.live.com/?v=2&cid=A9B6CFBF1C9F0219!154