Please keep us updated if any of these clear cases end up scratching the chrome bezel like crazy on your new 3g. On my original iPhone, the Belkin, Griffin, Agent 18 clear cases all ended up scratching the chrome on my iPhone bezel like crazy. I also read that silicon ones also end up scratching up the bezel.
I have both the Griffin Wave and the Agent18 (SHIELD) Clear Case for the 3G.
The Griffin Wave - Has the potential to scratch the chrome bezel. I tried 2 same cases: the first one did not and the 2nd one did. It's a gamble.
The Agent18 (SHIELD) Clease Case - Did not scratch mine at all. I noticed that the plastic around the chrome bezel does not touch the iPhone at all. I guess they listened to the complaints on the one for the 1st gen iPhone.
The only complaint I have about the Agent 18 is the back: it scratches. It does not scratch easily but it will still look like crap after a while. Mine is 4 days old and it already has lots. But all in all I am happy with it. I just wish they make a "smoked" version that won't attract sratches.