I talked to six southern California Apple stores, and here is the gist:
* No iPhones at any of these six stores
* Most ran out Friday/Saturday
* They don't know when they will get more, so "just keep calling"
* It hasn't happened before
This is tough one to figure. Strikes me that one of three things is going on:
1. Apple has a component issue and is doing a quiet recall
2. Apple has a supply issue with a major sole-source supplier
3. Apple is set to do a surprise launch of a 3G phone
This is, in fact, super odd for Apple, which might have trouble keeping up with demand at the start of a product cycle, but almost never has issues with established gear. When you see this sort of shortage on Apple laptops, for instance, it's almost always because they're about to announce new models.
As much as I'd like the 3G phone to be the reason for the shortage, I don't think we'll see that before the fall. My guess: problem with a supplier.