metacity can have keyboard shortcuts for moving the current window to
the edge of the screen.  You can bind these with gconf; for instance,
the following command will bind Ctrl-Alt-r to move the current
window to the right edge of the screen:

gconftool-2 --type=string --set /apps/metacity/window_keybindings/move_to_side_e '<Control><Alt>r'

This works fine with most windows, but Iceweasel windows immediately
move back to their original position.

See https://bugs.launchpad.net/ubuntu/+source/firefox-3.0/+bug/269809
for another report of this issue.

- Josh Triplett