I was selected as a Marshall Memorial Fellow last fall after being nominated and going through an extensive application and interview process.  Here is a bit of information about the fellowship program:

The German Marshall Fund is a nonpartisan American public policy and grantmaking institution dedicated to promoted greater cooperation and understanding between the United States and Europe.  The Marshall Memorial Fellowship Program provides a 3 to 4 week traveling program for "young leaders" across the United States.  During the program, Fellows develop a broad knowledge of political, economic, and social institutions and issues in their host countries. 

American Fellows travel as a group to Brussels, Belgium for briefings on European and transatlantic institutions before dividing into small groups to visit cities in Northern, Southern, and Central Europe.  In each city, the composition of the groups change to ensure that each Fellow travels with as many of his/her colleagues as possible.

More information can be found at  http://www.gmfus.org/fellowships/mmf.cfm