lf is a small utility to provide feedback when starting X11 applications.
Feedback can be given via four different indicators: an invisible window
(to be used in conjunction with a task pager like GNOMEs tasklist_applet or
KDEs Taskbar), an generic splashscreen, an hourglass attached to the mouse
cursor or an animated star.

This is the Linux version need for launching Linux applications from the
GNOME panel.

WWW: http://www.lysator.liu.se/~astrand/projects/xalf/