Grenade Stick

The Stick It/Stuck (or Grenade Stick in Halo 3) Medal is awarded for killing an opponent by sticking a Plasma or Spike Grenade to them. It is available in all Multiplayer gametypes and has a Bungie difficulty rating of 3 out of 10. It is represented by a bronze star with a blue star in it and a blue sphere inside of that. After you kill an opponent by sticking a grenade to them, a message appears on your screen that says: "You stuck (player)". This is also a medal in the Halo 3 campaign. Sticking is very easy to do if you have the Catch Skull, because when an enemy leans to throw a grenade at you, they cannot dodge any grenades thrown at them during this time.

Resemblences
The icon looks like the icon for the game Marble Blast Gold, which came default on all iBook G4s. However, this is thought to be coincidental, because Marble Blast came out in 2002.