Inrix is a company that uses data mining is a very interesting way - they combine department of transportation information with info from other sources to build models that predict what the traffic will be like at any given point and time and can then deduce how long it will take at that time to get from point A to point B.  Little is said on tools on their website, but this page displays one of their models using our dependency net viewer - which, of course, would only work if the model was in SQL Server Analysis Services.

Definately a cool and unique application of the DM technology in SQL Server!