My colleague Karlo Bartels made a very nice Excel 2010 Add-In:
To easily facilitate the process of displaying spatial objects in Excel, I created an Excel add-in that allows you to select a range of cells containing coordinates and show them on a map. To do this, the add-in accesses the Bing Maps SOAP Services. This is a set of programmable SOAP services that allow you to match addresses to a map (and much more). You will need a Bing Maps Application ID to access these services.
Check out his blog/article here (source and examples included!).