The holes allow players to send messages back and forth to the GM.
Yes, it just works with gravity.
You put you message in the metal orb, and put it into the "send" hole, and it comes down to the GM's feet. The GM station has 6 holes at the top to send to each player station. Each is marked with a little tag holder, so you can put the character's name in each spot. (Just another detail for fun.) The GM recieves messages back in 2 channels at the feet.
Not something that we'd do constantly or anything, but we would use it once or twice a session maybe.
We didn't make it that way because our playstyle was all about secrets; we just wanted to make the table as geeky as we could and we tried to make that aspect kind of fun.
Is it loud? Well, a little. All that needs to happen is to put some felt carpet in the channels, and it would be quiet. We never did it because it really wasn't that big of an issue. Everybody likes recieving notes from me, so I'd send everybody a note at the same time.
Arizona/Phoenix: I think I'd like it here a good deal more if I didn't have to drive so much. Sometimes Phoenix feels like LA jr.