login_screen.tcl in aMSN (aka Alvaro's Messenger) before 0.97.1 saves a password after logout, which allows physically proximate attackers to hijack a session by visiting an unattended workstation.
http://www.amsn-project.net/forums/index.php?topic=5317.0
http://sourceforge.net/project/shownotes.php?release_id=610067