To quote from our very own FAQ:

Halo is rumored to be the actual name for blam. It was first revealed in a leak from someone who had visited Bungie HQ and seen the game. Bungie has since clamped down on this rat, but it was too late and the name has already taken hold. MGL recently confirmed that Halo was a rumored name, so, somewhat unfortunately, it is public knowledge now.

But now, we ask you the more interesting question: what does the word Halo really mean? There is the obvious definition, but with Bungie, things aren't always as they appear and it still doesn't explain the reason for the choice of title.

If Halo is indeed the real name for blam, will it have some kind of heavenly connotation? Does Halo have any science-fiction significance?

To help us figure out its meaning, stop on by our forum and chuck your bit of research, opinion or whatnot into the pile and we'll see what conclusions we can draw.