It's not often that I'm impressed by something from Microsoft. I use Microsoft tools and software all the time but I'm usually not too excited about it. However... The Silverlight PivotViewer is awesome. But don't take my word for it - take a look yourself. Basically this control allows you to visualize and sort thousands of items at once. I won't go into detail...if you want to read more you can read Scott Guthrie's blog post about it.
The sample app they built works against Netflix’s database of instant watch movies. It works well and it’s pretty neat – something I might actually use! Take a look: http://netflixpivot.cloudapp.net/