Okay, I've copy/paste this because it was from me and I thought I was posting a cheat. So here it goes.

I haven’t tried it, but a friend of mine, who is pretty good at Halo 2, told me that in some level (probably in Legendary difficulty), there is a huge soccer ball. He said that it's probably at that "Ladies Like Big Guns" Level (The one where you drive the Scorpian Tank over the bridge and blast the living peace out of the Covenent to get to the Scarab. I don't know, but he said that there's one in Halo 2.