The Revolving Door

http://www.mindfully.org/GE/Revolving-Door.htm
http://www.cptech.org/ip/health/politics/revolvingdoor.html

[A 'short' list...]

Justin McCarthy, Billy Tauzin, Claude Burcky, Sean Darragh, Randall L. Tobias, Michael Friedman, Donald Rumsfeld, Deborah Steelman, Mitchell Daniels, Jr., Raymond V. Gilmartin, Anne Marie Lynch, Bill Walters, Gerald J. Mossinghoff, Dr. Harvey E. Bale, Jr., Alan F. Holmer, Susan K. Finston, Daniel L. Spiegel, Donald C. Alexander, S. Bruce Wilson, Edward J. Allera, Frank J. Donatelli, Barney J. Skladany, Jr., Thaddeus J. Burns, Elizabeth A. Hyman, Howard H. Baker, Jr., J. Keith Kennedy, George C. Montgomery, John C. Tuck, Peter Barton Hutt, Bruce N. Kuhlik, Jeanne S. Archibald, Stephan E. Lawton, Robert P. Brady, Michael R. Pollard, Thomas D. Parry, Romano Romani, Dennis DeConcini, Edward H. Baxter, Jack W. Martin, Linda A. Skladany, Shannon S. Davis, Judith A. Butler, Elizabeth A. Inadomi, Claudia James, Drew Littman, Anthony Podesta, Lee Skillington, Jeffrey Kushan, Barry B. Direnfeld, Lester S. Hyman, H.P. Goldfield, Richard A. Popkin and Gary D. Slaiman.
[...amongst others.]

[Sources: www.mindfully.org and www.cptech.org]