Cedric Shock:
channel-hue.gif
channel-intensity.gif
channel-saturation.gif
channel-his.gif
element-grid3.gif, module-r3.gif
status-failure.gif
status-running.gif
status-success.gif
element-3d.view.gif
element-icons.gif
drawmode-static.gif
drawmode-explore.gif

From BWidgets:
file-*.gif
edit-*.gif
status-out.gif (except status-gism.gif by M. Barton)
gui-rv.info.gif

Hamish Bowman:
module-d.nviz.gif
module-nviz.gif

Radim Blazek:
gui-cmd.gif

GRASS development team (GRASS logo):
gui-g.gif

Michael Barton:
Everything else