It'll look familiar if you've use AutoCAD Architecture before.
The i-drop indicator allows you to simply drag and drop content from the web into your drawing session or Revit project.
A great example of this is the furniture from Steelcase, here you can drag and drop (using the i-dropper) furniture symbols into your Revit project.
Very handy tool which works great. You can test that it works on the Autodesk web site where you can download i-drop.